Our profitability depends to a significant degree on our ability to accurately estimate and effectively manage expenses related to health benefits through, among other things, our ability to contract favorably with hospitals, physicians and other healthcare providers, as well as related administrative costs. For example, our government-sponsored health programs revenue is often based on bids submitted before the start of the initial contract year. If our actual medical expenses exceed our estimates for any reason, our health benefits ratio (HBR), or our expenses related to medical services as a percentage of premium revenues, would increase and our profits would decline. For example, late in the second quarter of 2025, data from an independent actuarial firm suggested a materially higher implied aggregate morbidity of the Marketplace membership as a whole than anticipated, resulting in a significant reduction of our expected net risk adjustment revenue for 2025. In addition, during 2025, our Medicaid membership had higher than expected medical costs, including due to unanticipated increased costs in behavioral health, home health and high-cost drugs. Because of the narrow margins of our health plan business, relatively small changes in our HBR can create significant changes in our financial results. Changes in healthcare regulations and practices, including due to the OBBBA, the level of utilization of healthcare services, including due to eligibility changes, benefit design, provider or consumer behavior changes, out-of-network utilization and pricing, medical claim submission patterns, including due to the use of artificial intelligence, hospital and pharmaceutical costs, including new high-cost specialty drugs, unexpected events, such as natural disasters, the effects of climate change, acts of war or aggression, geopolitical instability, major epidemics, pandemics and their resurgence, or newly emergent diseases, new medical technologies, increases in provider fraud, tariffs, unexpected increases in taxes and fees, including provider taxes, and other external factors, including general economic conditions such as interest rates, inflation and unemployment levels, are generally beyond our control and could reduce our ability to accurately predict and effectively control the costs of providing health benefits. Also, member and provider behavior could continue to be influenced by the uncertainty surrounding the availability, affordability, funding and access to health insurance, whether under Medicaid programs or the Affordable Care Act (ACA) or the OBBBA, including due to the expiration of the Enhanced Advance Premium Tax Credits (APTCs) and additional program integrity initiatives for Marketplace products.
In addition, as a result of the expiration of the public health emergency (PHE) due to the COVID-19 pandemic, and the resulting Medicaid redeterminations process, as well as changes in state benefit designs, we have continued to experience a higher HBR related to the remaining members, due to the acuity profile of this membership, as well as the gaps in eligibility for certain members who have rejoined the Medicaid plans. In particular, as part of the Medicaid rate setting process, state actuaries determine actuarial soundness of rates based on historical data. The delay in time between making claims payments and receiving rate adjustments when we experience an increased rate of change in medical expenses, whether due to the increased acuity profile of the membership or the increased utilization of health care services, such as behavioral health, home health and high-cost drugs, may cause the profitability of our Medicaid plans to be reduced. While we continue to work with our state partners to match rates to acuity to reflect more recent experience, such rate adjustments may be delayed or insufficient to offset the increased acuity.
Our medical expenses include claims reported but not paid, estimates for claims incurred but not reported, and estimates for the costs necessary to process unpaid claims at the end of each period. Our development of the medical claims liability estimate is a continuous process that we monitor and refine on a monthly basis as claims receipts and payment information as well as inpatient acuity information becomes available. As more complete information becomes available, we adjust the amount of the estimate, and include the changes in estimates in medical expenses in the period in which the changes are identified. Given the extensive judgment and uncertainties inherent in such estimates, there can be no assurance that our medical claims liability estimate will be accurate, and any adjustments to the estimate may unfavorably impact our results of operations and financial condition and may be material.
Assumptions and estimates are utilized in establishing premium deficiency reserves, when necessary. In the instance a premium deficiency reserve is necessary, if our assumptions are inaccurate, we may be required to increase our premium deficiency reserves which could have a material adverse effect on our results of operations and financial condition.
Additionally, when we commence operations in a new state or region or launch a new product, we have limited information with which to estimate our medical claims liability and continuity of care requirements, which can affect our ability to accurately predict medical claims. For a period of time after the inception of the new business, we base our estimates on government-provided historical actuarial data and limited actual incurred and received claims and inpatient acuity information. In addition, we have limited ability to manage the utilization of services until continuity of care requirements expire. For example, in 2025, we had higher utilization than we expected in several applied behavioral health services programs. The addition of new categories of eligible individuals, as well as evolving Health Insurance Marketplace plans and eligibility changes, may pose difficulty in estimating our medical claims liability.
From time to time in the past, our actual results have varied from our estimates, particularly in times of significant changes in the number and acuity profile of our members. If it is determined that our estimates are significantly different than actual results, our results of operations and financial condition could be materially adversely affected. In addition, if there is a significant delay in our receipt of premiums, our business operations, cash flows or earnings could be negatively impacted.