The U.S. healthcare system has long operated under a veil of ambiguity regarding the “prior authorization” process—a mechanism used by insurers to determine whether a requested medical service, treatment, or prescription is medically necessary before payment is approved. While insurers argue these requirements are essential to restrain costs and curb low-value care, nearly seven in ten insured adults report that the process acts as a significant burden, often leading to frustrating delays or denials of essential medical services.
In a landmark move toward administrative transparency, the Centers for Medicare and Medicaid Services (CMS) finalized a 2024 regulation designed to streamline and automate these processes. For the first time, Medicare Advantage, Medicaid, and Affordable Care Act (ACA) Marketplace insurers were required to publicly disclose their prior authorization metrics. As of March 2026, the industry has provided its first comprehensive glimpse into how these requests are handled—and the data reveals a landscape defined by significant variability and high appeal success rates.
The Chronology of Regulatory Reform
The journey toward this reporting requirement began as a response to growing public and provider outcry over the “black box” of insurer decision-making.
- February 2024: CMS published the final rule mandating that payers in Medicare Advantage, Medicaid/CHIP, and ACA Marketplace plans publicly post specific metrics, including approval and denial rates, for medical items and services (excluding prescription drugs).
- March 31, 2026: The deadline for insurers to publish their first annual performance report, covering the 2025 calendar year.
- June 2026: CMS issued updated guidance and templates, aiming to standardize the inconsistent reporting formats observed during the first filing cycle.
- Ongoing (2026-2027): Proposed federal rules, such as the 2026 Interoperability Standards, seek to expand reporting requirements to include prescription drugs and standardize the “denominator” metrics used by insurers to calculate their performance data.
Supporting Data: A Look Under the Hood
KFF’s comprehensive analysis of the 2025 reporting data—representing 71 million enrollees—uncovers stark differences in how insurers manage the flow of care.
Approval and Denial Trends
Across all market segments, insurers denied between 12% and 18% of standard prior authorization requests in 2025.
- Medicare Advantage: Insurers denied 12% of standard requests and 10% of expedited requests.
- Medicaid Managed Care: Denial rates sat at 14% for standard and 12% for expedited requests.
- ACA Marketplace: These plans saw the highest denial rates, with 18% of standard and 16% of expedited requests being rejected.
The variation between specific companies is even more dramatic. In the ACA Marketplace, for example, denial rates for standard requests ranged from a lean 3% at GuideWell to a staggering 25% at Centene. These disparities suggest that a patient’s experience with the healthcare system—and their ability to access care without friction—depends heavily on the specific insurance plan they choose.
The “Appeals Paradox”
Perhaps the most telling data point is the rate at which initial denials are overturned. When patients or providers persist through the arduous appeals process, a significant portion of initial denials are reversed.
- In Medicare Advantage, 67% of appealed standard denials were overturned.
- In Medicaid Managed Care, 47% were overturned.
- In the ACA Marketplace, 43% were overturned.
These high overturn rates raise critical questions: Are initial denials the result of overly aggressive automated systems, or do they simply reflect a failure to provide adequate initial documentation? The fact that a majority of appealed cases in Medicare Advantage end in a reversal suggests that the initial “no” is often not a final medical judgment, but rather a hurdle that can be cleared with additional administrative effort.
Median Response Times
The median time for a standard determination was roughly one day (approximately 22 hours) across all markets, well within federal mandates of 14–15 days. Expedited requests were processed even faster, typically within 10 to 19 hours. However, critics argue that “median” data can be misleading; it suggests the “typical” experience while potentially masking outliers—the cases where patients wait weeks, leading to significant, and sometimes fatal, health consequences.
Official Responses and Industry Context
The insurance industry is currently navigating a period of intense pressure. Many major carriers are voluntarily adopting “gold card” programs, where providers with high approval rates are exempted from prior authorization requirements. While insurers frame these as efforts to reduce administrative burden, they also complicate the data. If a carrier’s most efficient and compliant providers are exempt from the system, the remaining pool of requests might be skewed, potentially driving up denial rates for the rest of the network.
CMS has acknowledged that the first year of reporting was “messy.” Because the use of the CMS reporting template was not strictly mandatory in the initial cycle, insurers submitted data in varying formats, making head-to-head comparisons difficult. Some firms reported nationally, while others broke data down by state, obscuring local performance trends.
In response, CMS has made it clear that future reporting will be more prescriptive. By requiring that median response times of less than one day be reported in hours rather than rounded to “0,” and by mandating that insurers explain data quality concerns, the government is slowly tightening the screws on corporate accountability.
Implications for Consumers and Policy
The move toward transparency is intended to empower consumers, but the reality is more nuanced. As it stands, the average patient cannot easily navigate these technical reports to choose a plan with a higher approval rate.
1. The Need for Intermediaries
Because the data is currently presented in complex formats, it is likely that third-party organizations—researchers, patient advocacy groups, and health-literate journalists—will play the role of “translators.” These intermediaries will be essential in converting raw percentages into actionable information for the public.
2. The Limits of Aggregation
A primary concern remains the lack of numeric counts. Without knowing the total volume of requests, a 10% denial rate could represent 100 people or 100,000. CMS’s 2026 proposed rule to mandate the reporting of actual numeric counts is a necessary evolution to ensure that the public understands the true scale of the prior authorization landscape.
3. State-Level Innovation
While federal requirements set a floor, states like Massachusetts and Iowa are setting a higher ceiling. By requiring granular reporting—including the breakdown of denials by specific service categories (e.g., radiology, mental health, or physical therapy)—these states are enabling more precise regulatory action. Massachusetts, for instance, used this data to justify eliminating prior authorization for several routine services, a policy change that directly improves patient access.
4. The Path Forward
The overarching trend is clear: the era of opaque prior authorization is ending. Whether through the “Improving Seniors’ Timely Access to Care Act” or new CMS interoperability standards, the policy direction is firmly toward public disclosure.
For the average patient, the immediate benefit of these reports may be limited. However, for the health policy ecosystem, this data is transformative. It provides the empirical foundation needed to challenge industry practices, refine regulatory oversight, and eventually, shift the balance of power back toward the patient-provider relationship. As insurers prepare for the 2027 reporting cycle, they will do so under the watchful eye of a public and a government that are no longer satisfied with the status quo.
The transparency movement is not just about posting numbers on a website; it is about acknowledging that in a healthcare system, the speed and fairness of access are just as important as the cost of the services themselves.
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