Appeal win rates · California
How often are health insurance denials overturned?
When a California health plan denies care, an independent doctor can review the decision. Since 2021, reviewers overturned 65% of the 12,146 denials they looked at.
69%of “not medically necessary” denials overturned10,007 decisions
49%of “experimental or investigational” denials overturned2,099 decisions
42,749decisions since 2001, each published with the reviewer’s reasons
By type of care
Share of denials overturned on independent review. Pick one to see year-by-year results and recent decisions.
- Prescription drugs 75% 4,415 decisions since 2021
- Imaging, scans and lab tests 47% 1,298 decisions since 2021
- Mental health and addiction treatment 80% 1,588 decisions since 2021
- Medical equipment and supplies 56% 708 decisions since 2021
- Pain management 79% 941 decisions since 2021
- Orthopedic and spine surgery 30% 379 decisions since 2021
- Cancer treatment 53% 489 decisions since 2021
- General and weight-loss surgery 57% 241 decisions since 2021
- Physical, occupational and speech therapy 39% 159 decisions since 2021
- Reconstructive and plastic surgery 45% 286 decisions since 2021
- Ablation, magnetic stimulation and shock wave therapy 57% 210 decisions since 2021
- Autism treatment 51% 172 decisions since 2021
- Specialist and out-of-network referrals 52% 125 decisions since 2021
- Emergency and urgent care 45% 620 decisions since 2001
- Skilled nursing and inpatient rehab 24% 135 decisions since 2021
- Heart and vein procedures 62% 156 decisions since 2021
- Transplants, anesthesia and hyperbaric oxygen 42% 122 decisions since 2021
- Ear, nose and throat procedures 76% 191 decisions since 2021
- Acupuncture and alternative treatments 34% 414 decisions since 2001
- Hospital stays 62% 125 decisions since 2021
- Gynecologic procedures 50% 60 decisions since 2021
- Eye care 45% 228 decisions since 2001
- Neurosurgery 86% 50 decisions since 2021
- Dental and orthodontic care 55% 168 decisions since 2001
- Chiropractic care 32% 158 decisions since 2001
- Home health care 47% 153 decisions since 2001
- Urology procedures 41% 105 decisions since 2001
- Medical transportation 55% 66 decisions since 2001
- Preventive screenings 27% 44 decisions since 2001
What these numbers mean
- These are decisions by independent doctors in California’s Independent Medical Review, run by the Department of Managed Health Care for the plans it regulates. They show how past denials ended, not the odds for any one case.
- “Overturned” means the reviewer sided with the patient and the plan had to cover the care. Only denials that reached independent review are counted.
- Plans in other states, and self-funded employer plans, use other independent reviewers; their results aren’t in this data.
Source: California Department of Managed Health Care, Independent Medical Review (IMR) Determinations, California Health and Human Services Open Data Portal, updated June 1, 2026. 42,749 decisions from 2001 to 2026 (2026 partial).