Arthur J. Gallagher & Co.: 10-K Risk Factor Changes

•Global economic and geopolitical events, such as fluctuations in interest and inflation rates; geo-economic fragmentation and protectionism; a recession or economic downturn; a U.S. government shutdown or political violence; and instability, including as a result of armed conflicts in Ukraine, the Middle East, Latin America and the Caribbean could adversely affect our results of operations and financial condition. •Economic conditions that result in financial difficulties for underwriting enterprises or lead to reduced risk-taking capital capacity could adversely affect our results of operations and financial condition. •We have historically acquired large numbers of insurance brokers, benefit consulting firms and, to a lesser extent, third party claims administration and risk management firms. We may not be able to continue such an acquisition strategy in the future and there are risks associated with such acquisitions, which could adversely affect our growth and results of operations. •Damage to our reputation and culture could have a material adverse effect on our business. •Our sustainability aspirations, goals and initiatives, and our public statements and disclosures regarding them, expose us to numerous risks. •If we are unable to apply technology, data analytics and AI effectively in driving value for our clients through technology-based solutions or gain internal efficiencies and effective internal controls through the application of technology and related tools, our operating results, client relationships, organic and inorganic growth and compliance programs could be adversely affected. •We are subject to risks associated with AI. •Our success depends, in part, on our ability to attract and retain qualified talent, including our senior management team. •Business disruptions could have a material adverse effect on our operations, damage our reputation and impact client relationships. •Our business or reputation could be harmed by our reliance on third-party providers. •Sustained increases in compensation expense and the cost of employee benefits could reduce our profitability. •Our substantial operations outside the U.S. expose us to risks different than those we face in the U.S. •Changes in tax laws could adversely affect us. •We face significant competitive pressures in each of our businesses. •Volatility or declines in premiums or other adverse trends in the insurance industry may seriously undermine our profitability. •Contingent and supplemental revenues we receive from underwriting enterprises are less predictable than standard commission revenues, and any decrease in the amount of these forms of revenue could adversely affect our results of operations. •We face a variety of risks in our benefit consulting operations distinct from those we face in our insurance brokerage operations. •We face a variety of risks in our third-party claims administration operations that are distinct from those we face in our brokerage and benefit consulting operations. 11 11 11 Table of Contents Table of Contents

•Global economic and geopolitical events, such as fluctuations in interest and inflation rates; geo-economic fragmentation and protectionism; a recession or economic downturn; a potential U.S. government shutdown or gridlock over increasing the debt ceiling and political violence, and instability, including as a result of armed conflicts in Ukraine and the Middle East, could adversely affect our results of operations and financial condition. Global economic and geopolitical events, such as fluctuations in interest and inflation rates; geo-economic fragmentation and protectionism; a recession or economic downturn; a potential U.S. government shutdown or gridlock over increasing the debt ceiling and political violence, and instability, including as a result of armed conflicts in Ukraine and the Middle East, could adversely affect our results of operations and financial condition. •Economic conditions that result in financial difficulties for underwriting enterprises or lead to reduced risk-taking capital capacity could adversely affect our results of operations and financial condition. Economic conditions that result in financial difficulties for underwriting enterprises or lead to reduced risk-taking capital capacity could adversely affect our results of operations and financial condition. •We have historically acquired large numbers of insurance brokers, benefit consulting firms and, to a lesser extent, third party claims administration and risk management firms. We may not be able to continue such an acquisition strategy in the future and there are risks associated with such acquisitions, which could adversely affect our growth and results of operations. We have historically acquired large numbers of insurance brokers, benefit consulting firms and, to a lesser extent, third party claims administration and risk management firms. We may not be able to continue such an acquisition strategy in the future and there are risks associated with such acquisitions, which could adversely affect our growth and results of operations. •We face additional risks relating to acquisitions that are larger than our usual tuck-in acquisitions, including that these acquisitions will not perform as expected and that we cannot successfully integrate complex operations. We face additional risks relating to acquisitions that are larger than our usual tuck-in acquisitions, including that these acquisitions will not perform as expected and that we cannot successfully integrate complex operations. •Damage to our reputation and culture could have a material adverse effect on our business. Damage to our reputation and culture could have a material adverse effect on our business. •Our sustainability aspirations, goals and initiatives, and our public statements and disclosures regarding them, expose us to numerous risks. Our sustainability aspirations, goals and initiatives, and our public statements and disclosures regarding them, expose us to numerous risks. •If we are unable to apply technology, data analytics and AI effectively in driving value for our clients through technology-based solutions or gain internal efficiencies and effective internal controls through the application of technology and related tools, our operating results, client relationships, organic and inorganic growth and compliance programs could be adversely affected. If we are unable to apply technology, data analytics and AI effectively in driving value for our clients through technology-based solutions or gain internal efficiencies and effective internal controls through the application of technology and related tools, our operating results, client relationships, organic and inorganic growth and compliance programs could be adversely affected. •We are subject to risks associated with AI. We are subject to risks associated with AI. •Our success depends, in part, on our ability to attract and retain qualified talent, including our senior management team. Our success depends, in part, on our ability to attract and retain qualified talent, including our senior management team. •Business disruptions could have a material adverse effect on our operations, damage our reputation and impact client relationships. Business disruptions could have a material adverse effect on our operations, damage our reputation and impact client relationships. •Sustained increases in compensation expense and the cost of employee benefits could reduce our profitability. Sustained increases in compensation expense and the cost of employee benefits could reduce our profitability. •Our substantial operations outside the U.S. expose us to risks different than those we face in the U.S. Our substantial operations outside the U.S. expose us to risks different than those we face in the U.S. •Changes in tax laws could adversely affect us. Changes in tax laws could adversely affect us. •We face significant competitive pressures in each of our businesses. We face significant competitive pressures in each of our businesses. •Volatility or declines in premiums or other adverse trends in the insurance industry may seriously undermine our profitability. Volatility or declines in premiums or other adverse trends in the insurance industry may seriously undermine our profitability. •Contingent and supplemental revenues we receive from underwriting enterprises are less predictable than standard commission revenues, and any decrease in the amount of these forms of revenue could adversely affect our results of operations. Contingent and supplemental revenues we receive from underwriting enterprises are less predictable than standard commission revenues, and any decrease in the amount of these forms of revenue could adversely affect our results of operations. •We face a variety of risks in our benefit consulting operations distinct from those we face in our insurance brokerage operations. We face a variety of risks in our benefit consulting operations distinct from those we face in our insurance brokerage operations. 11 11 11 •We face a variety of risks in our third-party claims administration operations that are distinct from those we face in our brokerage and benefit consulting operations. We face a variety of risks in our third-party claims administration operations that are distinct from those we face in our brokerage and benefit consulting operations. •Climate risks, including the risk of an economic crisis, risks associated with the physical effects of climate change and disruptions caused by the transition to a low-carbon economy, could adversely affect our business, results of operations and financial condition. Climate risks, including the risk of an economic crisis, risks associated with the physical effects of climate change and disruptions caused by the transition to a low-carbon economy, could adversely affect our business, results of operations and financial condition.

Our acquisition program has been an important part of our historical growth, particularly in our brokerage segment, and we believe that similar acquisition activity will be important to maintaining comparable growth in the future. Failure to successfully identify and complete acquisitions would likely result in slower growth. Continuing consolidation in our industry and a high level of interest in acquiring insurance brokers on the part of private equity firms, private equity-backed consolidators and newly public insurance brokers has, in some cases, made, and could in the future make, appropriate acquisition targets more difficult to identify and more expensive. Even if we are able to identify appropriate acquisition targets, we may not have sufficient capital to fund acquisitions, be able to execute transactions on favorable terms or integrate targets in a manner that allows us to realize the benefits we have historically experienced from acquisitions. When regulatory approval of acquisitions is required, our ability to complete acquisitions may be limited by an ongoing regulatory review or other issues with the relevant regulator. Our ability to finance and integrate acquisitions may also decrease if we complete a greater number of larger acquisitions than we have historically. See the paragraph below regarding larger acquisitions. See also Note 3 to our 2025 consolidated financial statements for information regarding the size of transactions in the reporting period. Post-acquisition risks include poor cultural fit and risks relating to retention of personnel, retention of clients, entry into unfamiliar or complex markets or lines of business, contingencies or liabilities not covered by or in excess of escrowed or indemnified amounts (such as those arising from unlawful sales practices and violations of sanctions laws or anti-corruption laws including the FCPA and U.K. Bribery Act), risks relating to ensuring compliance with licensing and regulatory requirements, tax and accounting issues, the risk that an acquisition distracts management and personnel from our existing business, and integration difficulties relating to accounting, information technology (which we refer to as IT), 13 13 13 Table of Contents Table of Contents pay equity, or human resources, some or all of which could have an adverse effect on our results of operations and growth. The failure of acquisition targets to achieve anticipated revenue and earnings levels could result in goodwill impairment charges. Additionally, through our acquisitions, we may enter new lines of business or offer new services within existing lines of business. For example, our acquisitions of Woodruff Sawyer and Caytons Law added legal consulting services related to directors' and officers’ liability insurance and a U.K.-based claims and legal solutions firm. These new businesses may pose additional risks or increased regulatory burden. Integration efforts relating to larger acquisitions (including, for example, AssuredPartners, the largest acquisition in our history) are more complex, including with respect to technology systems, which may divert management’s attention and resources and could adversely affect our operating results. In addition, we have made certain assumptions relating to these acquisitions that may be inaccurate, including as a result of the failure to realize expected benefits, higher than expected integration costs and unknown liabilities as well as general economic and business conditions. These assumptions relate to various matters, including projections of future revenues, non-GAAP measures, expenses and expense allocation; our ability to maintain, develop and deepen relationships with employees, including key brokers, and clients; the amount of goodwill and intangibles; our ability to realize anticipated cost savings and revenue synergies; and other unforeseen compliance, financial and strategic risks.

Our ordinary-course acquisition program has been an important part of our historical growth, particularly in our brokerage segment, and we believe that similar acquisition activity will be important to maintaining comparable growth in the future. Failure to successfully identify and complete acquisitions would likely result in slower growth. Continuing consolidation in our industry and a high level of interest in acquiring insurance brokers on the part of private equity firms, private equity-backed consolidators and newly public insurance brokers has, in some cases, made, and could in the future make, appropriate acquisition targets more difficult to identify and more expensive. Even if we are able to identify appropriate acquisition targets, we may not have sufficient capital to fund acquisitions, be able to execute transactions on favorable terms or integrate targets in a manner that allows us to realize the benefits we have historically experienced from acquisitions. When regulatory approval of acquisitions is required, our ability to complete acquisitions may be limited by an ongoing regulatory review or other issues with the relevant regulator. Our ability to finance and integrate acquisitions may also decrease if we complete a greater number of larger acquisitions than we have historically. See the risk factor below regarding larger acquisitions. See also Note 3 to our 2024 consolidated financial statements for information regarding the size of transactions in the reporting period. Post-acquisition risks apply both to our normal-course and larger acquisitions described in the risk factor below and include poor cultural fit and risks relating to retention of personnel, retention of clients, entry into unfamiliar or complex markets or lines of business, contingencies or liabilities not covered by or in excess of escrowed or indemnified amounts (such as those arising from violations of sanctions laws or anti-corruption laws including the FCPA and U.K. Bribery Act) risks relating to ensuring compliance with licensing and regulatory requirements, tax and accounting issues, the risk that an acquisition distracts management and personnel from our existing business, and integration difficulties relating to accounting, information technology (which we refer to as IT), pay equity, or human resources, some or all of which could have an adverse effect on our results of operations and growth. The failure of acquisition targets to achieve anticipated revenue and earnings levels could result in goodwill impairment charges. Additionally, through our acquisitions, we may enter new lines of business or offer new services within existing lines of business. For example, our acquisition of Redington and My Plan Manager added U.K.‑regulated investment consulting services and Australia-regulated disability plan management services to our operations. These new businesses may pose additional risks or increased regulatory burden.

Compensation expense and the cost of employees’ medical and other employee benefits, substantially affect our profitability. In the past, we have occasionally experienced significant increases in these costs as a result of macro-economic factors beyond our control, including wage inflation and increases in health care costs. In 2025, our health care costs rose by approximately 20% compared to 2024 (includes impact of inflation, increased utilization and increased headcount) and our consolidated compensation expense ratio in 2025 as a percent of total consolidated revenue at 56.2% decreased slightly compared to 2024. Although we have actively sought to control increases in compensation expense and the cost of employee benefits, we can make no assurance that we will succeed in limiting future cost increases, and continued upward pressure in these costs could reduce our profitability.

Compensation expense and the cost of employees’ medical and other benefits, substantially affects our profitability. In the past, we have occasionally experienced significant increases in these costs as a result of macro-economic factors beyond our control, including wage inflation and increases in health care costs. Our compensation expense ratio in 2024 as a percent of total revenue remained the same as in 2023 at 56.4%. Although we have actively sought to control increases in compensation expense and the cost of employee benefits, we can make no assurance that we will succeed in limiting future cost increases, and continued upward pressure in these costs could reduce our profitability.

We prepare our financial statements in accordance with U.S. generally accepted accounting principles (which we refer to as GAAP). These accounting principles require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of our consolidated financial statements. We are also required to make certain judgments and estimates that affect the disclosed and recorded amounts of revenues and expenses related to revenue recognition and deferred costs - see Note 4 to our 2025 consolidated financial statements. We periodically evaluate our estimates and assumptions, including those relating to the valuation of goodwill and other intangible assets, investments, income taxes, revenue recognition, deferred costs, stock-based compensation, claims handling obligations, retirement plans, litigation and contingencies. We base our estimates on historical experience and various assumptions that we believe to be reasonable based on specific circumstances. Such estimates and assumptions could change in the future as more information becomes known, which could impact the amounts reported and disclosed in our consolidated financial statements. Further, in 2022, the U.S. enacted the Inflation Reduction Act (which we refer to as the IRA) which, among other things, implements a corporate book minimum tax and an excise tax on stock buy backs. While guidance is still being issued and the administration may enact significant amendments to the IRA, our current understanding of the IRA suggests that we will not face significant impacts. Additionally, in July 2025, the U.S. enacted the One Big Beautiful Bill Act which includes significant provisions, such as the permanent extension of certain expiring provisions of the Tax Cuts and Jobs Act, modifications to the international tax framework and the restoration of favorable tax treatment for certain business provisions. The legislation has multiple effective dates, with certain provisions effective in 2025 and others implemented through 2027. The application of the OBBBA did not have any material impact on our financial statements for 2025. As additional guidance relating to the IRA, OBBBA, and upcoming amendments are released, our estimates related to tax and other liabilities arising under these frameworks may change. Additionally, changes in accounting standards (see Note 2 to our 2025 consolidated financial statements) could increase costs to the organization and could have an adverse impact on our future financial position and results of operations.

We prepare our financial statements in accordance with U.S. generally accepted accounting principles (which we refer to as GAAP). These accounting principles require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, and the disclosure of contingent assets and liabilities at the date of our consolidated financial statements. We are also required to make certain judgments and estimates that affect the disclosed and recorded amounts of revenues and expenses related to revenue recognition and deferred costs - see Note 4 to our 2024 consolidated financial statements. We periodically evaluate our estimates and assumptions, including those relating to the valuation of goodwill and other intangible assets, investments, income taxes, revenue recognition, deferred costs, stock-based compensation, claims handling obligations, retirement plans, litigation and contingencies. We base our estimates on historical experience and various assumptions that we believe to be reasonable based on specific circumstances. Such estimates and assumptions could change in the future as more information becomes known, which could impact the amounts reported and disclosed in our consolidated financial statements. 27 27 27 Further, in 2022, the U.S. enacted the Inflation Reduction Act (which we refer to as the IRA) which, among other things, implements a corporate book minimum tax and an excise tax on stock buy backs. While guidance is still being issued and the new administration may enact significant amendments to the IRA, our current understanding of the IRA suggests that we will not face significant impacts. As additional guidance relating to the IRA and upcoming amendments are released, our estimates related to the IRA may change. Additionally, changes in accounting standards (see Note 2 to our 2024 consolidated financial statements) could increase costs to the organization and could have an adverse impact on our future financial position and results of operations.

We use AI in our business, including with respect to services provided to our clients. We have internal policies and controls governing development, procurement, deployment and the use of AI by our employees designed to align with globally recognized AI principles, maintain trust with clients and protect the company from cybersecurity threats, breaches of data privacy and intellectual property, E&O liability and regulatory enforcement risk; however, our employees could violate these policies and they or external threat actors could circumvent our controls and expose us to such risks. Furthermore, our exposure to these risks may increase if our vendors, suppliers, or other third-party providers employ AI in relation to the products or services they provide to us, as we have limited control over such use in third-party products or services. These risks include, among others, the input of confidential information, including material non-public information, in contravention of our policies or contractual restrictions to which any of the foregoing are subject, or in violation of applicable laws or regulations, including those relating to data protection and AI. This could result in such information becoming part of a data set that is accessible by other third-party AI applications and users. Additionally, AI heavily relies on the collection and analysis of extensive data sets. The third-party models underlying our AI tools may be inadequately designed, implemented or trained, and due to the impracticality of incorporating all relevant data into the models used by AI, it is inevitable that data sets within these models will contain information that has inaccuracies and errors, and potential biases. This could potentially render such models inadequate or flawed, leading to outputs surfacing third-party intellectual property or that contain information that is biased, unethical, discriminatory, incomplete, inaccurate, misleading or poor-quality that could negatively impact the effectiveness of the technology or our services. We are exposed to the risks associated with these inaccuracies, errors and biases, along with the adverse impacts that such flawed models could have on our business and operations. Furthermore, there is a risk that the use of AI may subject the company to reputational harm and liability related to governance and ethical issues and potential litigation from third-party intellectual property holders. The increasing adoption of AI technologies by cyber threat actors presents a significant and evolving risk to our company. These actors may leverage AI to develop more sophisticated and targeted cyberattacks, including advanced phishing schemes, malware, and data exfiltration techniques, which could compromise our controls and systems, client data, and proprietary information. Such incidents could result in operational disruptions, financial losses, reputational damage, regulatory scrutiny, and potential legal liabilities. As the capabilities of AI-driven threats continue to advance, the complexity and scale of cyber risks we face may increase, necessitating ongoing investment in robust cybersecurity measures and threat mitigation strategies. 15 15 15 Table of Contents Table of Contents AI and its applications are developing rapidly. The use of this technology by our clients or underwriting enterprises may impact the way our business operates, and its use by our competitors and new market entrants with competing services derived from their AI capabilities may give them a competitive advantage. We cannot predict the effect of these changes at this time. or example, they may decrease the demand for our services or negatively affect our assumptions regarding the competitive landscape of our business. Further, the rapid development of these technologies may require significant efforts to upskill or reskill existing employees. Consequently, it is difficult to predict all risks associated with this new technology, which may eventually impact our business, results of operations, or financial condition. See also “Changes in data privacy and protection laws and regulations, or any failure to comply with such laws and regulations, could adversely affect our business and financial results.”

We use AI in our business, including with respect to services provided to our clients. We have internal policies and controls governing the development, procurement, deployment and use of AI by our employees designed to align with globally recognized AI principles, maintain trust with clients and protect the company from cybersecurity threats, breaches of data privacy and intellectual property, E&O liability and regulatory enforcement risk; however, our employees could violate these policies and they or external threat actors could circumvent our controls and expose us to such risks. Furthermore, our exposure to these risks may increase if our vendors, suppliers, or other third-party providers employ AI in relation to the products or services they provide to us, as we have limited control over such use in third-party products or services. These risks include, among others, the input of confidential information, including material non-public information, in contravention of our policies or contractual restrictions to which any of the foregoing are subject, or in violation of applicable laws or regulations, including those relating to data protection and AI. This could result in such information becoming part of a dataset that is accessible by other third-party AI applications and users. Additionally, AI heavily relies on the collection and analysis of extensive data sets. Due to the impracticality of incorporating all relevant data into the models used by AI, it is inevitable that data sets within these models will contain inaccuracies and errors, and potential biases. This could potentially render such models inadequate or flawed, negatively impacting the effectiveness of the technology or our services. We are exposed to the risks associated with these inaccuracies, errors and biases, along with the adverse impacts that such flawed models could have on our business and operations. Furthermore, governance and ethical issues relating to the use of AI may also result in reputational harm and liability. AI and its applications are developing rapidly. The use of this technology by clients or underwriting enterprises may impact the way our business operates, and its use by our competitors and new market entrants with competing services derived from their AI capabilities may give them a competitive advantage. We cannot predict the effect of these changes at this time, for example, they may decrease the demand for our services or negatively affect our assumptions regarding the competitive landscape of our business. Further, the rapid development of these technologies may require significant efforts to upskill or reskill existing employees. Consequently, it is difficult to predict all risks associated with this new technology, which may eventually impact our business, results of operations, or financial condition. See also “Changes in data privacy and protection laws and regulations, or any failure to comply with such laws and regulations, could adversely affect our business and financial results.”

Many of our activities throughout the world, especially regulated businesses such as our insurance brokerage, securities broker-dealer and investment advisory services, are subject to supervision and regulations promulgated by regulatory or self-regulatory bodies such as the SEC, the NYSE, the DOJ, the IRS, the Financial Crimes Enforcement Network, the FTC and FINRA in the U.S., the FCA in the U.K., the Australian Securities and Investments Commission in Australia and insurance regulators in nearly every jurisdiction in which we operate. Our retirement-related consulting and investment advisory services are subject to pension law and financial regulation in many countries. Our activities are also subject to a variety of other laws, rules and regulations addressing licensing, cybersecurity, data privacy, AI, wage-and-hour standards, employment and labor relations, competition, anti-corruption, currency, the conduct of business, reserves and the amount of local investment with respect to our operations in certain countries. For example, the DOJ updated its guidance on corporate compliance programs to include AI risk management. These and other forms of regulatory action could reduce our profitability or growth by increasing the costs of compliance, increasing the risk of costly enforcement actions, restricting the products or services we sell, the markets we enter, the methods by which we sell our products and services, or the prices we can charge for our services and the form of compensation we can accept from our clients, underwriting enterprises and third parties. As our operations grow around the world, it is increasingly difficult to monitor and enforce regulatory compliance across the organization. A compliance failure by even one of our smallest branches could lead to a loss of reputation in the local market, and litigation and/or disciplinary actions that may include compensating clients for loss, the imposition of penalties, and/or the loss of our authorization to operate. In all such cases, we would also likely incur significant internal investigation costs and legal fees. The global nature of our operations increases the complexity and cost of compliance with laws and regulations, including increased staffing needs, the development of new policies, procedures and internal controls and providing training to employees in multiple locations, adding to our cost of doing business. Many of these laws and regulations may have differing or conflicting legal standards across jurisdictions, increasing further the complexity and cost of compliance. We experience substantial geopolitical and regulatory changes on a real-time basis, which may lead to uncertainty and increase the complexity, difficulty, and cost of compliance. In emerging markets and other jurisdictions with less developed legal systems, local laws and regulations may not be established with sufficiently clear and reliable guidance to provide us with adequate assurance that we are aware of all necessary licenses to operate our business, that we are operating our business in a compliant manner, or that our rights are otherwise protected. In addition, major political and legal developments in jurisdictions in which we do business may lead to new regulatory costs and challenges. For example, China has in place a “blocking” statute similar to that of the E.U. requiring compliance with certain Chinese laws if they conflict with U.S. laws. Rising global tensions and protectionism may also lead other countries to adopt similar blocking statutes, which could make it more difficult and costly for us to expand our operations globally. Changes in legislation or regulations and actions by regulators, including changes in administration and enforcement policies, or the failure of state and local governments to follow through on agreed-upon state and local tax credits or other tax related incentives, could adversely affect our results of operations or require operational changes that could result in lost revenues or higher costs or hinder our ability to operate our business. 26 26 26 Table of Contents Table of Contents For example, the method by which insurance brokers are compensated has received substantial scrutiny in the past because of the potential for conflicts of interest. The potential for conflicts of interest arises when a broker is compensated by two parties in connection with the same or similar transactions. The vast majority of the compensation we receive for our work as insurance and reinsurance brokers is in the form of retail commissions and fees. We receive additional revenue from underwriting enterprises, separate from retail commissions and fees, including, among other things, contingent and supplemental revenues and payments for consulting and analytics services we provide them. Future changes in the regulatory environment may impact our ability to collect these revenues. Adverse regulatory, legal or other developments regarding these revenues could have a material adverse effect on our business, results of operations or financial condition, expose us to negative publicity and reputational damage and harm our relationships with clients, underwriting enterprises or other business partners. In addition, climate change and sustainability issues remain a significant focus for investors, clients and other business partners, while regulatory approaches across jurisdictions continue to vary widely. Some jurisdictions, such as the U.K., Australia and the State of California, are intensifying regulation and enforcement with respect to climate-related disclosures, where others are moving towards deregulation – for example, at the U.S. federal level the SEC abandoned the defense of the climate-related disclosures rule and the E.U. approved the Omnibus I directive that reduced significantly the entities subject to, and the requirements of, the Corporate Sustainability Reporting Directive (which we refer to as CSRD) and the Corporate Sustainability Due Diligence Directive (which we refer to as CSDDD). In addition, the State of Texas recently issued an opinion on the legality of corporate DEI programs taking the position that such programs are potentially unlawful under certain circumstances. Navigating these inconsistent and evolving rules may demand substantial effort and resources, potentially diverting management’s attention. Failure to effectively navigate these complexities could harm our reputation and strain relationships with regulators, investors, clients, and other business partners, which may adversely affect our business, operating results and financial condition.

Many of our activities throughout the world, especially regulated businesses such as our insurance brokerage, securities broker-dealer and investment advisory services, are subject to supervision and regulations promulgated by regulatory or self-regulatory bodies such as the SEC, the NYSE, the DOJ, the IRS, the Financial Crimes Enforcement Network, the FTC and FINRA in the U.S., the Financial Conduct Authority in the U.K., the Australian Securities and Investments Commission in Australia and insurance regulators in nearly every jurisdiction in which we operate. Our retirement-related consulting and investment advisory services are subject to pension law and financial regulation in many countries. Our activities are also subject to a variety of other laws, rules and regulations addressing licensing, cybersecurity, data privacy, AI, wage-and-hour standards, employment and labor relations, competition, anti-corruption, currency, the conduct of business, reserves and the amount of local investment with respect to our operations in certain countries. For example, the DOJ revised its Corporate Criminal Enforcement Policies and Practices to include a section on the use of personal devices and third-party messaging applications, indicating that their use poses significant risk to companies and suggesting that it intends to investigate seriously whether companies have ensured that data from these sources is preserved for investigations. The DOJ also updated its guidance on corporate compliance programs to include AI risk management. These and other forms of regulatory action could reduce our profitability or growth by increasing the costs of compliance, increasing the risk of costly enforcement actions, restricting the products or services we sell, the markets we enter, the methods by which we sell our products and services, or the prices we can charge for our services and the form of compensation we can accept from our clients, underwriting enterprises and third parties. As our operations grow around the world, it is increasingly difficult to monitor and enforce regulatory compliance across the organization. A compliance failure by even one of our smallest branches could lead to a loss of reputation in the local market, and litigation and/or disciplinary actions 26 26 26 that may include compensating clients for loss, the imposition of penalties, and/or the loss of our authorization to operate. In all such cases, we would also likely incur significant internal investigation costs and legal fees. The global nature of our operations increases the complexity and cost of compliance with laws and regulations, including increased staffing needs, the development of new policies, procedures and internal controls and providing training to employees in multiple locations, adding to our cost of doing business. Many of these laws and regulations may have differing or conflicting legal standards across jurisdictions, increasing further the complexity and cost of compliance. In emerging markets and other jurisdictions with less developed legal systems, local laws and regulations may not be established with sufficiently clear and reliable guidance to provide us with adequate assurance that we are aware of all necessary licenses to operate our business, that we are operating our business in a compliant manner, or that our rights are otherwise protected. In addition, major political and legal developments in jurisdictions in which we do business may lead to new regulatory costs and challenges. For example, China adopted a “blocking” statute similar to that of the EU requiring compliance with certain Chinese laws if they conflict with U.S. laws. Rising global tensions and protectionism may also lead other countries to adopt similar blocking statutes, which could make it more difficult and costly for us to expand our operations globally. Changes in legislation or regulations and actions by regulators, including changes in administration and enforcement policies, or the failure of state and local governments to follow through on agreed-upon state and local tax credits or other tax related incentives, could adversely affect our results of operations or require operational changes that could result in lost revenues or higher costs or hinder our ability to operate our business. For example, the method by which insurance brokers are compensated has received substantial scrutiny in the past because of the potential for conflicts of interest. The potential for conflicts of interest arises when a broker is compensated by two parties in connection with the same or similar transactions. The vast majority of the compensation we receive for our work as insurance and reinsurance brokers is in the form of retail commissions and fees. We receive additional revenue from underwriting enterprises, separate from retail commissions and fees, including, among other things, contingent and supplemental revenues and payments for consulting and analytics services we provide them. Future changes in the regulatory environment may impact our ability to collect these revenues. Adverse regulatory, legal or other developments regarding these revenues could have a material adverse effect on our business, results of operations or financial condition, expose us to negative publicity and reputational damage and harm our relationships with clients, underwriting enterprises or other business partners. In addition, as regulators and investors increasingly focus on climate change and other sustainability issues, we are exposed to the risk of frameworks and regulations being adopted that require significant effort to comply with, and re ill-adapted to our operations, particularly with respect to our larger-than usual acquisitions that may have their own sustainability programs and may have complied with sustainability regulations in the past in a way that may differ substantially from our sustainability program and strategy. For example, in 2023, pursuant to the CSRD, which we expect will result in disclosure obligations in future years for us and some of our EU subsidiaries, the first set of ESRS was developed by the EFRAG and adopted by the EU. EFRAG will continue to issue sector-specific and non-EU applicable ESRS in the coming years, with such standards to be tailored to EU policy positions which may be different or contradictory with those applicable in other jurisdictions such as the ISSB) and the TCFD framework. In the U.K., our business is subject to a number of disclosure obligations under different sustainability frameworks, such as the TCFD. Australia enacted mandatory disclosures based on the ISSB standards in 2024, and other jurisdictions, such as Canada and New Zealand, have announced that they plan to implement ISSB-based disclosures. There is further uncertainty in this space as the SEC’s new climate change disclosure requirements enacted in 2024 are currently being challenged in legal proceedings and are expected to be struck down, while the state of California has enacted disclosure rules, which we expect will require us, among other things, to publish our consolidated carbon emissions. Compliance with such differing and uncertain rules and frameworks requires significant effort and could divert management’s attention and resources, which could adversely affect our operating results.

Our benefit consulting operations face a variety of risks distinct from those faced by our brokerage operations. The portion of our revenue derived from consulting engagements and special project work is more vulnerable to reduction, postponement, cancellation or non-renewal during an economic downturn than traditional insurance brokerage commissions. A portion of our benefit consulting operation revenue is tied to assets invested by our clients, and when investment returns are adversely affected that portion of our revenue is negatively impacted. Certain areas within our retirement consulting practice may attract a higher level of regulatory scrutiny due to regulators’ historical interest in such matters, including pension-related products and investment advisory and broker-dealer services. In addition, we have made significant investments in product and knowledge development to assist clients as they navigate the complex regulatory requirements relating to employer-sponsored healthcare. New laws or regulations reducing employer-sponsored health insurance, by limiting or eliminating tax-advantaged employer-sponsored benefits or otherwise, could impact clients’ demand for our services. If we are unable to adapt our services to changes in the legal and regulatory landscape around employer-sponsored benefits, our results of operations could be adversely impacted.

Our benefit consulting operations face a variety of risks distinct from those faced by our brokerage operations. The portion of our revenue derived from consulting engagements and special project work is more vulnerable to reduction, postponement, cancellation or non-renewal during an economic downturn than traditional insurance brokerage commissions. For instance, we experienced a decline in such revenue during the economic downturn triggered by the COVID-19 pandemic. In the event of a future recession or economic downturn, we could again experience deterioration in these sources of revenue. A portion of our benefit consulting operation revenue is tied to assets invested by our clients, and when investment returns are adversely affected that portion of our revenue is negatively impacted. Certain areas within our retirement consulting practice may attract a higher level of regulatory scrutiny due to regulators’ historical interest in such matters, including pension-related products and investment advisory and broker-dealer services. In addition, we have made significant investments in product and knowledge development to assist clients as they navigate the complex regulatory requirements relating to employer-sponsored healthcare. New laws or regulations reducing employer-sponsored health insurance, by limiting or eliminating tax-advantaged employer-sponsored benefits or otherwise, could impact clients’ demand for our services. If we are unable to adapt our services to changes in the legal and regulatory landscape around employer-sponsored benefits, our results of operations could be adversely impacted. We closed the acquisition of Buck in second quarter 2023 and Redington in fourth quarter 2024. Buck is the largest acquisition in the history of our benefit consulting operations and represents a material portion of its revenue. As such, the integration of Buck into our existing operations requires a more significant effort and involves additional risks compared to our typical acquisitions. Redington is an FCA-regulated investment consulting firm focused on pension funds, wealth managers and institutional investors with a large footprint in the U.K., which may expose us to greater liability than our typical acquisitions. See also “We face additional risks relating to acquisitions that are larger than our usual tuck-in acquisitions” described above.

We generated tax credits under IRC Section 45 from 2009 to 2021. As of December 31, 2025, we had generated a total of $1,706 million in IRC Section 45 tax credits, of which approximately $1,102 million have been used to offset U.S. federal tax liabilities and $604 million remain unused and available to offset future U.S. federal tax liabilities. Our ability to use tax credits under IRC Section 45 depends upon the operations in which we invested having satisfied the conditions set forth in IRC Section 45. These include, among others, the “placed-in-service” condition and requirements relating to qualified emissions reductions, coal sales to unrelated parties and at least one of the operations’ owners qualifying as a “producer” of refined coal. While we have received some degree of confirmation from the IRS relating to our ability to claim these tax credits, the IRS could ultimately determine that the operations did not satisfy the conditions set forth in IRC Section 45. The IRS audited a number of these operations. Such audits were either closed with no adjustments or, in one instance, the relevant partnership defended its position in court and prevailed. There is a risk that foreign laws will not protect the intellectual property associated with The Chem-Mod™ Solution to the same extent as U.S. laws, leaving us vulnerable to companies outside the U.S. who may attempt to copy such intellectual property. In addition, other companies may make claims of intellectual property infringement with respect to The Chem-Mod™ Solution. Litigation is inherently uncertain and it is not possible for us to predict the ultimate outcome of any future claims against us by other parties.

We generated tax credits under IRC Section 45 from 2009 to 2021. As of December 31, 2024, we had generated a total of $1,706.1 million in IRC Section 45 tax credits, of which approximately $1,003.9 million have been used to offset U.S. federal tax liabilities and $702.2 million remain unused and available to offset future U.S. federal tax liabilities. Our ability to use tax credits under IRC Section 45 depends upon the operations in which we invested having satisfied the conditions set forth in IRC Section 45. These include, among others, the “placed-in-service” condition and requirements relating to qualified emissions reductions, coal sales to unrelated parties and at least one of the operations’ owners qualifying as a “producer” of refined coal. While we have received some degree of confirmation from the IRS relating to our ability to claim these tax credits, the IRS could ultimately determine that the operations did not satisfy the conditions set forth in IRC Section 45. The IRS audited a number of these operations. Such audits were either closed with no adjustments or, in one instance, the relevant partnership defended its position in court and prevailed. The ongoing implementation of Pillar 2 in the U.S. and around the world could also negatively impact our ability to use these tax credits in the timeframe and manner that would be beneficial to us. Similarly, the law permitting us to claim IRC Section 29 tax credits (related to our prior synthetic coal operations) expired on December 31, 2007. At December 31, 2024, we had exposure with respect to $108.0 million of previously earned tax credits under IRC Section 29. We believe our claim for IRC Section 29 tax credits in 2007 and prior years was in accordance with IRC Section 29 and four private letter rulings previously obtained by IRC Section 29 related limited liability companies in which we had an interest. We understand these private letter rulings were consistent with those issued to other taxpayers and we have received no indication from the IRS that it will seek to revoke or modify them. In addition, the IRS audited certain of the IRC Section 29 facilities without requiring any changes. There is a risk that foreign laws will not protect the intellectual property associated with The Chem-Mod™ Solution to the same extent as U.S. laws, leaving us vulnerable to companies outside the U.S. who may attempt to copy such intellectual property. In addition, other companies may make claims of intellectual property infringement with respect to The Chem-Mod™ Solution. 28 28 28 Litigation is inherently uncertain and it is not possible for us to predict the ultimate outcome of any future claims against us by other parties.

Differing views and regulatory approaches regarding sustainability have made compliance with regulations, frameworks and stakeholder expectations increasingly complex and subject to risk. Our sustainability-related aspirations, goals and initiatives face scrutiny from the investment community, regulators, current and potential clients, employees, potential acquisition targets, and other stakeholders related to sustainability. This includes scrutiny regarding our goal to reach operational net zero carbon emissions (Scope 1 and Scope 2) by 2050 and our interim goal of a 50% reduction in such emissions, on a per employee basis, by 2030. We anticipate the same level of scrutiny with respect to any other goals, targets and objectives we may announce in the future, and our methodologies and timelines for pursuing them. We could become the target of litigation, investigations or public criticism alleging that our sustainability efforts are anti-competitive, discriminatory or otherwise unlawful. For example, the State of Texas recently issued an opinion on the legality of corporate diversity, equity and inclusion (DEI) programs taking the position that such programs are potentially unlawful under certain circumstances. On the other hand, our failure or perceived failure to pursue or fulfill our sustainability-related goals, targets and objectives, to comply with ethical, social, environmental or other standards, regulations or expectations, or to satisfy various sustainability reporting standards, which vary widely across different jurisdictions, could also make us the target of litigation, investigations or public criticism. Any resulting erosion of trust and confidence could make it difficult for us to attract acquisition targets or attract and retain clients, employees or investors; result in lower sustainability ratings, exclusion of our stock from sustainability-oriented indices, and reduced demand for our stock from sustainability-focused or anti-ESG investment funds; increase our cost of borrowing; or harm our relationships with regulators and the communities in which we operate. See also “We are subject to regulation worldwide. If we fail to comply with regulatory requirements or if regulations change in a way that adversely affects our operations, we may not be able to conduct our business, or we may be less profitable.” 14 14 14 Table of Contents Table of Contents

The increased focus on sustainability has made compliance with regulations, frameworks and stakeholder expectations increasingly complex. Our business faces increased scrutiny from the investment community, clients, employees, potential acquisition targets, regulators and other stakeholders related to sustainability. This includes scrutiny regarding our goal to reach operational net zero carbon emissions (Scope 1 and Scope 2) by 2050 and our interim goal of a 50% reduction in such emissions, on a per employee basis, by 2030. We anticipate the same level of scrutiny with respect to any other goals, targets and objectives we may announce in the future, and our methodologies and timelines for pursuing them. We may also face scrutiny, including private litigation or government enforcement actions, relating to our long-standing inclusion and diversity initiatives. Heightened scrutiny, including a growing backlash against sustainability initiatives, has increased the risk that we could be perceived as, or accused of, making inaccurate or misleading statements, commonly referred to as “greenwashing” and “greenhushing,” and could harm our reputation. Similarly, our failure or perceived failure to pursue or fulfill our goals, targets and objectives, to comply with ethical, social environmental or other standards, regulations or expectations, which are continuously evolving, or to satisfy various reporting standards with respect to these matters, could have the same negative impacts, as well as expose us to government enforcement actions and private litigation. Any resulting erosion of trust and confidence or the perception among some stakeholders that we are overly focused on sustainability could make it difficult for us to attract acquisition targets or attract and retain clients, employees or investors; result in lower sustainability ratings, exclusion of our stock from sustainability-oriented indices, and reduced demand for our stock from sustainability-focused or anti-ESG investment funds; increase our cost of borrowing; or harm our relationships with regulators and the communities in which we operate. See also “We are subject to regulation worldwide. If we fail to comply with regulatory requirements or if regulations change in a way that adversely affects our operations, we may not be able to conduct our business, or we may be less profitable.”

We operate in various jurisdictions and are subject to changes in applicable tax laws, treaties, or regulations in those jurisdictions. A material change in the tax laws, treaties, or regulations, or their interpretation, of any jurisdiction with which we do business, or in which we have significant operations, could adversely affect us. For example, in the Organization for Economic Cooperation and Development (which we refer to as the OECD) continues to issue reports and recommendations as part of its Base Erosion and Profit Shifting project (which we refer to as BEPS) and in 2021, it announced that 136 countries and tax jurisdictions agreed to implement a new Pillar 2 approach to international taxation. Pillar 1 exempts regulated financial institutions and we believe we qualify for such exemption. Many countries in which we do business have adopted, or are expected to adopt, these rules which will change various aspects of the existing framework under which our tax obligations are determined. For example, the U.K., the majority of the E.U., Canada, Australia and New Zealand have now adopted nearly all aspects of these rules with limited variation from the OECD model rules. Other jurisdictions in which we do business also reacted to these efforts; for example, Bermuda enacted a corporate tax regime for the first time in 2023, which became effective in 2025. On January 5, 2026, OECD released additional administrative guidance on the application of Pillar 2 global minimum tax rules, which are designed to ensure that large multinational enterprise (MNE) groups are subject to a minimum effective tax rate of 15% in each jurisdiction in which they operate. This guidance introduces a package of new and expanded safe harbors and simplification measures, including a “side-by-side” safe harbor regime applicable to certain U.S.-parent MNE groups, extensions and modifications to existing transitional safe harbors, and additional rules addressing the treatment of tax incentives and effective tax rate calculations. The most significant element of this guidance is the “side-by-side” safe harbor which is intended to coordinate the Pillar 2 global minimum tax regime with certain domestic minimum tax systems, including those in the U.S. Subject to eligibility requirements and elections, this safe harbor may substantially reduce or eliminate the application of Pillar 2 “top-up taxes,” including the Income Inclusion Rule and Undertaxed Profits Rule for affected MNE groups for fiscal years beginning on or after January 1, 2026. These developments, once enacted into domestic law by Pillar 2 adopters, have the potential to significantly de-risk Pillar 2 exposure for U.S. multinationals like Gallagher. Whether those enactments take effect in 2026 or later, they will need to be monitored and anticipated top-ups adjusted to reflect those enactment dates. Regardless of the adoption of this new guidance, the domestic minimum top-up aspect of Pillar 2 (referred to as “QDMTT”) and its related compliance aspects will remain for all multinationals that operate in jurisdictions that have enacted it. We anticipate further significant developments across several jurisdictions in which we operate in 2026 and 2027. Should the jurisdictions in which we operate, and those in which we and our subsidiaries are based, choose not to implement the OECD’s January 2026 guidance in their tax treaties and domestic tax laws, particularly if the U.S. does not adopt Pillar 2, although we do not anticipate a material financial impact, we could be adversely affected by a top-up.

We operate in various jurisdictions and are subject to changes in applicable tax laws, treaties, or regulations in those jurisdictions. A material change in the tax laws, treaties, or regulations, or their interpretation, of any jurisdiction with which we do business, or in which we have significant operations, could adversely affect us. For example, the OECD continues to issue reports and recommendations as part of its Base Erosion and Profit Shifting project (which we refer to as BEPS) and in 2021, it announced that 136 countries and tax jurisdictions agreed to implement a new Pillar 2 approach to international taxation. Pillar 1 exempts regulated financial institutions and we believe we qualify for such exemption. Pillar 2 will establish a global minimum tax rate of 15%, such that multinational enterprises with an effective tax rate in a jurisdiction below this minimum rate will need to pay additional tax, which could be collected by the parent company’s tax authorities if that parent country adopts Pillar 2 or by those in other countries, depending on whether and how each country implements the OECD’s approach in its tax treaties and domestic tax legislation. The first detailed draft rules under that approach were published in December 2021. The new approach came into effect in 2023 in certain jurisdictions, and different countries have implemented the necessary rules in different ways, through their individual agreement to tax treaty changes and through changes to their own domestic tax laws. Many countries in which we do business have adopted, or are expected to adopt, these rules which will change various aspects of the existing framework under which our tax obligations are determined. For example, the U.K., the majority of the EU, Canada, Australia and New Zealand have now adopted nearly all aspects of these rules with limited variation from the OECD model rules. Other jurisdictions in which we do business are also reacting to these efforts; for example, Bermuda enacted a corporate tax regime for the first time in 2023, which has become effective starting 2025. We anticipate further significant developments across several jurisdictions in which we operate in 2025 and 2026. Depending on how the jurisdictions in which we operate, and those in which we and our subsidiaries are based, choose to implement the OECD’s approach in their tax treaties and domestic tax laws, particularly if the U.S. does not adopt Pillar 2, we could be adversely affected due to our income being taxed at higher effective rates, once these new rules come into force.