DEEP DIVE
📊 The data is public: payers overturn 3 of 4 denials they write
Kaiser Permanente's Southern California Medicare Advantage plan denied 19.48% of standard prior authorizations in 2025, then overturned 74.52% of the denials that were appealed. Those are Kaiser's own numbers, filed last month because CMS finally forced them to be.
The first public reporting deadline under the CMS Interoperability and Prior Authorization Final Rule passed March 31, 2026. Medicare Advantage plans, Medicaid managed care organizations, CHIP, and Marketplace QHPs had to post CY2025 prior auth metrics covering approvals, denials, decision timeliness, and appeal outcomes. ERISA self-insured plans are exempt. Drug PA sits under a separate rule that hasn't been finalized. The Trump administration said last June it won't actively enforce the deadline, and compliance has been uneven, with some payers posting clean reports and others publishing framing instead. The ones who did file created something the industry has never had: a named, per-contract accounting of how often the denial machine is actually wrong.
The Kaiser numbers, in detail
On Kaiser SoCal's flagship MA contract (H0524), there were 143,690 standard non-urgent PA requests in 2025. The filing shows 27,992 were denied. Of those, 310 were appealed, and 231 came back overturned in favor of the member. That is the three-of-four headline.
Inside Kaiser, the regional spread tells its own story. SoCal's H0524 denied at roughly 2x the rate of every other Kaiser region: Northern California 10.53%, Northwest 12.56%, Colorado 9.64%, Mid-Atlantic 5.51%. Every Kaiser region overturned more than half of appealed denials. SoCal's overturn rate was the highest of the group.
Kaiser's number sits inside the long-run norm
KFF has been publishing this benchmark for years using aggregate CMS Part C data. In their 2024 MA analysis, insurers processed 52.8 million determinations, denied 4.1 million of them, and overturned 80.7% of appealed denials. Their 2023, 2022, 2021, 2020, and 2019 reports all landed between 80% and 84%. At the payer level, 2022 CMS data put Centene at 95.3%, Aetna at 90.8%, Anthem at 89.2%, UHC at 86.1%, Cigna at 85.3%, Humana at 68.4%. The median sat around 86%.
The 2022 OIG audit went further and manually reviewed 250 denial case files. It found 13% of MA prior auth denials should have been approved under Medicare coverage rules, most often because MA plans applied clinical criteria stricter than Medicare itself required. We flagged the same systematic pattern on the downcoding side last summer. Nothing about the March 31 filings reveals a new problem. They confirm a pattern regulators have flagged for seven years.
The appeal gap is the profit model
Only 310 of Kaiser SoCal's 27,992 denials were appealed at all. That is 1.1%. KFF's MA-wide appeal rate is 11.5%. Change Healthcare's analysis of 441 million claims found 35% to 65% of denied claims are never reworked.
Hospitals and physician groups spent $19.7 billion in 2022 fighting denials (AHA), with per-claim appeal costs at $57.23 and climbing 30.5% year over year (Premier 2023). Premier put 2023 denial-fighting spend at $25.7 billion, $18 billion of which was on denials that eventually got overturned. The economics tell the payer what to do next: deny broadly and make appeals expensive enough that most providers won't bother. The filed data shows the strategy working. 98.9% of Kaiser SoCal's denials stood, and roughly three quarters of the few that got challenged were reversed.
Takeaways
Use the public overturn rate as a negotiation lever. When a denial lands that contradicts the payer's own filed data, cite it. "Your CY2025 CMS filing shows three of four of these denials get overturned on appeal. I'd like to skip the round trip and have this approved now." Payers haven't had to defend their own numbers in a negotiation before, and the approach pairs with keeping your contracts close at hand.
Move your appeal rate from 20% to 80%+. The average practice appeals around 20% of denials. Kaiser SoCal saw 1.1%. Getting your appeal rate to 80% on medical-necessity denials, at an industry-average 80% overturn, recovers roughly 4x the revenue with no new billable work. Assign an owner, set a weekly review cadence, and track appealed-vs-denied alongside the other early-warning metrics.
Treat the filings as a benchmark for your own numbers. Pull your MA denial rate and overturn rate for last year. Compare them to the payer's posted rates. If the payer denies 15% and you're appealing 2%, you know where the leak is. If your overturn rate on appeal is below the payer's posted rate, you're under-documenting. The public filings give you an external yardstick you didn't have before.
Payers will adapt. Expect tighter PA criteria framed as clinical clarity, more denial volume shifted to post-claim processes that sit outside the rule's scope, selective gold-carding for cooperative specialties, and narrower AI use in MA post-acute decisions. Transactional denial counts are harder to game than quality scores, but scope contraction and reclassification are real. The 74% becomes a rhetorical fixture. What it moves is denial volume, not denial rate.
UPCOMING EVENTS + REMINDERS
📆 Mark your calendars:
Arcutis Biotherapeutics Q1 2026 earnings call — May 6, 2026, 4:30 PM ET. ARQT reports first-quarter financial results and hosts a conference call with a business update on roflumilast franchise performance.
Washington SB 5395 effective date (prior authorization reform) — June 11, 2026. New transparency, accountability, and AI-use standards for prior authorization determinations take effect for Washington-regulated health plans.
CMS-0062-P public comment deadline (drug e-PA proposed rule) — June 15, 2026. Final day to submit comments on the 2026 Interoperability Standards and Prior Authorization for Drugs proposed rule extending electronic prior authorization to drugs.
Virginia HB736 — prior authorization minimum-duration law enacted — Signed April 6, 2026 (tracking for effective date). Establishes a six-month floor for initial prior authorizations and 12 months for continued authorizations across drugs and certain services.
Until next week,
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