OON Referral denials: 27.3% overturned by independent reviewers
In 183 California IMR decisions from 2002 to 2025, reviewers overturned the plan 50 times (27.3%). In the last five years: 34.8% of 23. Denials reach IMR only when a member appeals all the way; read the caveats below before generalising.
By diagnosis
| Diagnosis category | Decisions | Overturned | Last 5 years |
|---|---|---|---|
| Cancer | 29 | 41.4% | 50.0% of 4 |
| Orth/Musculoskeletal | 29 | 13.8% | 25.0% of 4 |
| Mental Disorder | 14 | 57.1% | 100.0% of 1 |
| Digestive System/ GI | 14 | 14.3% | — |
| CNS/ Neuromusc Dis | 11 | 0.0% | 0.0% of 1 |
| Pediatrics | 10 | 20.0% | 0.0% of 1 |
| Cardiac/Circ Problem | 10 | 30.0% | 33.3% of 3 |
| Immuno Disorders | 9 | 22.2% | — |
| Ears/Nose/Throat | 8 | 12.5% | — |
| OB-GYN/ Pregnancy | 7 | 28.6% | — |
| GU/ Kidney Disorder | 7 | 28.6% | 25.0% of 4 |
By year (last five)
| Year | Decisions | Overturned |
|---|---|---|
| 2021 | 9 | 44.4% |
| 2022 | 2 | 50.0% |
| 2023 | 5 | 20.0% |
| 2024 | 3 | 0.0% |
| 2025 | 4 | 50.0% |
What the findings mention
| What the findings mention | Decisions | Overturned | All decisions here |
|---|---|---|---|
| Published evidence citedThe findings refer to peer-reviewed or published evidence. | 43 | 23.3% | 27.3% |
| Records did not supportThe findings say the documentation did not show what was needed (usually an upheld denial). | 32 | 3.1% | 27.3% |
| Urgent or emergencyThe findings mention urgency. | 8 | 37.5% | 27.3% |
| Prior therapies failedThe findings mention treatments that were tried without adequate response. | 5 | 20.0% | 27.3% |
| Guidelines or criteria citedThe findings cite guidelines, criteria or a standard of care. | 3 | 33.3% | 27.3% |
Keyword matches on the reviewer’s findings, not causes. A tag that appears mostly in overturned decisions is worth documenting in an appeal; it is not a guarantee.
From recent overturned decisions
“The physician reviewer found that a patient has requested authorization and coverage for a tertiary level of care for a bilateral mastectomy with immediate reconstruction (bilateral deep flap reconstruction). Medical literature notes that bilateral deep inferior epigastric perforator flap reconstruction is associated with higher procedural complexity and increased risk of complications compared to unilateral procedures. The procedure in this case …”
“The physician reviewer found that a patient has requested authorization and coverage for referral to a tertiary care gynecology specialist.On review of the available documentation, the requested referral to a tertiary care gynecology specialist is medically necessary for the evaluation of this patient. Per the National Institute for Health and Care Excellence (NICE), the diagnosis and management of endometriosis requires …”
“Nature of Statutory Criteria/Case Summary: The patient has requested authorization and coverage for a referral to a multidisciplinary autonomic program that includes Neurology, Cardiology, Gastroenterology, Pain Medicine, Rheumatology, Immunology, Hematology, Dermatology, Psychiatry, and Pathology specializing in autonomic disorders. A multidisciplinary autonomic program is an interdisciplinary program that provides collaborative and comprehensive care for patients with disorders of the autonomic nervous …”
- California only: these are decisions by independent reviewers under California's IMR program (plans regulated by the Department of Managed Health Care). Other states and self-funded employer plans use different reviewers and rules.
- Selection: only denials that a member took all the way to IMR appear. Most denials are never appealed, and the ones that reach an external reviewer are not a random sample.
- Overturned means the reviewer disagreed with the plan; it does not mean the treatment worked or that a similar request will be approved.
- Argument tags are keyword matches on the reviewer's findings. They describe what the findings mention, not why the case was decided.
- Categories are DMHC's own labels (treatment sub-category and diagnosis category); 'Other' is a catch-all and is excluded from rankings.
Source: California Department of Managed Health Care, Independent Medical Review (IMR) Determinations, Trend (CHHS Open Data). Public California government data; Apellica's aggregates and tags are CC BY 4.0.
Questions
How often were OON Referral denials overturned?
In 183 California IMR decisions from 2002 to 2025, reviewers overturned the plan 50 times (27.3%). In the last five years: 34.8% of 23.
What did the reviewers' findings mention in overturned cases?
The table on this page counts keyword matches in the findings: prior therapies tried, contraindications, guidelines cited, published evidence, whether the records supported the request. They describe what the findings say, not why the case was decided.
Does a California IMR result apply to my plan?
Only California plans regulated by the Department of Managed Health Care go to IMR. Other states and self-funded employer plans use different reviewers, but the reasoning is the same kind: criteria, documentation and alternatives. Use the findings as a guide to what to document.
Related: California appeal rights · California external-review reversal rate · The levers library · CSV
Independent reviewers reverse plans when the record answers the criteria. Upload the denial letter; a senior reviewer reads it within 24 hours and tells you in writing whether it can be appealed and how. $0 upfront, 10% of what is recovered, nothing if we do not recover. Not a law firm.