On this page
A decade of Independent Medical ReviewIMR Independent Medical Review. The appeal from a UR denial. 30 days (10 if the dispute is only over drugs on the MTUS Drug List). outcomes in California workers’ compensation. Updated annually when the Division of Workers’ Compensation releases its IMR Report. Current through the 2026 report analyzing 2025 data, released May 19, 2026.
The headline: only about 1 in 10 denied treatments gets overturned — and it has been that way for ten years. In 2025, IMR issued 152,351 final determinations covering 266,756 disputed treatment requests, and upheld the utilization reviewUR Utilization Review. The process that approves, modifies, or denies each treatment request. A modification is a denial of what it left out. decision on 89.8% of those requests. Across 2016–2025 the overturn rate has never exceeded 12.7% and never fallen below 7.2%.
Reuse this data. These figures are drawn from public DWCDWC Division of Workers’ Compensation, part of the Department of Industrial Relations. Administers the system. Information Services Center: 1-800-736-7401. reports. Charts, tables, and figures on this page may be reproduced freely with attribution to Solov & Teitell and a link back. If you are a journalist, researcher, union representative, or treating physician and want the underlying extraction, contact us.
Why this page exists
California publishes IMR outcome data every year in a PDF. This page puts ten years of the DWC’s figures in one place, in a form an injured worker, a treating physician or a reporter can use — updated once a year, at a stable URL, with a source for every figure.
Determinations and outcomes by year
| Year | Applications received | Eligible | Treatment requests decided | UR upheld | UR overturned |
|---|---|---|---|---|---|
| 2025 | 201,037 | 152,832 | 266,756 | 89.8% | 10.2% |
| 2024 | 199,651 | 148,106 | 248,716 | 87.3% | 12.7% |
| 2023 | 175,027 | 133,093 | 227,611 | 89.8% | 10.2% |
| 2022 | 170,855 | 129,298 | 240,976 | 91.8% | 8.2% |
| 2021 | 178,927 | 136,828 | 264,196 | 92.8% | 7.2% |
| 2020 | 184,100 | 139,411 | 270,281 | 90.5% | 9.5% |
| 2019 | 222,236 | 165,610 | 319,505 | 89.6% | 10.4% |
| 2018 | 252,565 | 185,783 | 360,124 | 89.7% | 10.3% |
| 2017 | 248,251 | 175,118 | 343,451 | 91.7% | 8.3% |
| 2016 | 249,436 | 172,452 | 343,141 | 91.6% | 8.4% |
Upheld and overturned are shares of the treatment requests decided at IMR (DWC 2026 IMR Report, Table 9), not of applications: one determination can decide several requested treatments.
Ten-year totals: 2,082,085 applications. Highest overturn rate: 2024, at 12.7%. Lowest: 2021, at 7.2%.
Two things stand out. Application volume fell 32% from its 2018 peak of 252,565 to a low of 170,855 in 2022, then climbed back above 200,000 in 2025 (201,037). And the overturn rate has stayed within a ten-year band of 5.5 percentage points, through a pandemic, a formulary rollout and several regulatory changes.
2025 detail. 152,351 determinations issued — 152,243 standard and 108 expedited. Expedited review was 0.07% of all determinations. Duplicate applications were 16.6% of filings. Ineligible applications fell 7.9% from 2024, while untimely filings rose 5.4%. Average turnaround: 6–7 days from receipt of complete records; under 30 days from the notice of assignment (monthly averages of 24 to 32 days); 2 days for expedited. 99.99% of standard determinations issued within the 30-day statutory deadline — only 13 cases statewide exceeded it.
Outcomes by treatment category, 2025
Based on 266,756 disputed treatment requests. (Requests exceed determinations because one IMR can cover several requested services.)
| Category | Requests | Share | Upheld | Overturned |
|---|---|---|---|---|
| Programs (functional restoration etc.) | 3,882 | 1.5% | 81.5% | 18.5% |
| Behavioral / mental health | 4,443 | 1.7% | 81.7% | 18.3% |
| Evaluation & management | 12,486 | 4.7% | 83.2% | 16.8% |
| Diagnostic testing / imaging | 30,531 | 11.4% | 86.3% | 13.7% |
| Surgery | 18,360 | 6.9% | 89.4% | 10.6% |
| Home health | 1,730 | 0.6% | 89.8% | 10.2% |
| DMEPOS | 26,619 | 10.0% | 89.9% | 10.1% |
| Pharmaceuticals | 81,576 | 30.6% | 91.0% | 9.0% |
| Rehabilitation (PT/OT/chiro/acupuncture) | 61,055 | 22.9% | 91.1% | 8.9% |
| Accommodation | 235 | 0.1% | 91.9% | 8.1% |
| Injections | 24,978 | 9.4% | 93.3% | 6.7% |
| Transportation | 861 | 0.3% | 96.4% | 3.6% |
Pharmaceuticals and rehabilitation together account for 53.5% of the treatment requests decided at IMR in 2025, and both sit near a 9% overturn rate, below the 10.2% overall.
The categories with the highest overturn rates — programs, behavioral health, evaluation and management — are together under 8% of volume. The disputes that happen most often are overturned less often than average.
A note on injections. Effective April 1, 2026, spinal injections were added to the list of treatments requiring prospective utilization review even during the first 30 days after injury. That is a category with a 93.3% uphold rate. More injection requests may now go through UR, and at IMR injection denials were overturned 6.7% of the time in 2025. We will track whether the 2026 data reflects it.
Pharmaceutical outcomes by drug class, 2025
| Drug class | Requests | Share of pharma | Overturned |
|---|---|---|---|
| Antidepressants | 2,170 | 2.7% | 24.1% |
| NSAIDs | 10,488 | 12.9% | 18.9% |
| Antiulcer agents | 2,337 | 2.9% | 18.3% |
| Other classes | 7,876 | 9.7% | 14.7% |
| Laxatives | 1,589 | 1.9% | 12.3% |
| Anti-epilepsy | 7,440 | 9.1% | 7.2% |
| Opioids | 17,506 | 21.5% | 6.8% |
| Sedatives / hypnotics | 1,618 | 2.0% | 6.4% |
| Topical analgesics | 15,405 | 18.9% | 6.0% |
| Benzodiazepines | 867 | 1.1% | 5.0% |
| Anti-infectives | 1,417 | 1.7% | 4.9% |
| Muscle relaxants | 12,863 | 15.8% | 1.4% |
Shares of pharmaceutical requests are our calculation from DWC Table 12.
Muscle relaxant denials are upheld 98.6% of the time. Antidepressants, at 24.1% overturned, are more than seventeen times likelier to be reversed.
Trend: pharmaceuticals fell from 32.7% of all disputed requests in 2024 to 30.6% in 2025. Opioids fell from 23.9% of pharmaceutical requests in 2024 to 21.5% in 2025.
Who decides
85% of 2025 cases were handled by California-licensed reviewers; 77% of decisions came from board-certified specialists in occupational medicine, orthopedic surgery, pain medicine, or physical medicine and rehabilitation.
| Specialty | Cases | Share |
|---|---|---|
| Occupational Medicine | 63,561 | 41.7% |
| Orthopedic Surgery | 21,907 | 14.4% |
| Physical Medicine & Rehabilitation | 17,238 | 11.3% |
| Pain Medicine | 14,264 | 9.4% |
| Emergency Medicine | 12,901 | 8.5% |
Reviewer identities are confidential. Neither the injured worker, the treating physician, nor the employer learns who decided the case.
Who is requesting
The DWC report does not publish physician-concentration data. These figures come from the California Workers’ Compensation Institute, which describes itself as a private, nonprofit organization of insurers licensed to write workers’ compensation in California, with public and private self-insured employers as associate members.
| Period | Top 1% of requesting physicians | Share of disputed requests | Top 10 physicians |
|---|---|---|---|
| 12 months ending March 2025 | 81 doctors | 42.2% | 10.9% |
| 2019 | 106 doctors | 41.2% | 9.9% |
Seven of the top ten in the 2025 period repeated from the prior year.
In the 12 months ending March 2025, 81 physicians — the top 1% of requesters — accounted for 42.2% of the disputed service requests that went to IMR. The figure is read two ways: that a small group of prescribers drives system cost, or that a small group of physicians keeps requesting care that most others no longer request. The figure itself settles neither.
What the numbers do and do not mean
They do not mean IMR is pointless. IMR is the route the Labor Code gives for disputing medical necessity. If no one requests it in time, the utilization review decision stands — and it stays in effect for 12 months against a further request for the same treatment by the same physician or practice group, unless the request is supported by a documented change in the facts.
They do not mean 90% of denials are correct. They mean 90% are upheld by a paper review against guidelines that carry a statutory presumption of correctness. Those are different claims, and the data cannot distinguish them.
They do mean the timing of the UR decision deserves a look first. The medical question is hard to appeal: a successful WCABWCAB Workers’ Compensation Appeals Board. The court system that decides these cases. 23 district offices statewide. appeal produces a second IMR by a different review organization (or, if none is available, a different reviewer at the original one), not a treatment authorization. But under Dubon II (WCAB en banc, 2014), a utilization review decision is invalid and not subject to IMR only if it is untimely — and then the Appeals Board may decide medical necessity on substantial medical evidence. Every other dispute about a UR decision goes to IMR. Timeliness is a question the data above says nothing about, and it is the question worth asking first.
They also mean the category matters. A denied treatment program (programs: 18.5% overturned in 2025) and a denied muscle relaxant (1.4%) face very different odds at IMR.
Sources and method
All primary figures are drawn from the DWC’s annual IMR reports. Determination counts, eligibility figures, category breakdowns, drug-class breakdowns, and reviewer specialty data for 2025 come from the 2026 IMR Report: Analysis of 2025 Data (data extraction date March 5, 2026; released May 19, 2026 per DWC Newsline 2026-43). Year-over-year figures for 2016–2024 come from that report’s trend tables · 8 CCR § 9792.9.7(b)(8) · Labor Code § 4610.6(f) · § 4610.5(b) · § 4610(k) · § 4610.6(i) · Labor Code § 4610.6(h) · 8 CCR § 9792.9.7 · § 9792.9.8 · Labor Code § 4610.5(h)(1).
Two limitations we will not paper over.
Figures for 2013–2015 — IMR’s first three years — are not included, because the current DWC report’s trend table begins at 2016 and we have not independently verified the archived reports. We would rather show a ten-year series we can stand behind than a thirteen-year one we cannot.
CWCI’s series counts determination letters; DWC counts applications and final determinations. The two are not directly comparable and we do not mix them in a single table.
One trap worth flagging for anyone else working with this data. The California Health & Human Services open data portal hosts a dataset titled “Independent Medical Review (IMR) Determinations, Trend” covering 2001 to present. That is the Department of Managed Health Care’s IMR program for commercial health plans — a different statutory scheme entirely. It is not workers’ compensation data, and it is easy to mistake for it.
Next update
May 2027, on release of the DWC 2027 IMR Report covering 2026 data. That report will be the first to include data under the utilization review regulations that took effect April 1, 2026 — about nine months of 2026 — including the rules for treatment in the first 30 days after injury, the five-business-day formulary timeframe that cannot be extended, and the addition of spinal injections to the list of treatments that need prospective review. The first full calendar year under the new rules will be 2027. We will publish the comparison.
Compiled and reviewed by Jamey Teitell, Partner and Trial Attorney, Law Offices of Solov & Teitell, APC. Last updated August 19, 2026.
Related: Utilization Review — every deadline and what makes a denial invalid · Independent Medical Review — the process end to end
General information about California law, not legal advice about your case.
Reviewed by Jamey Teitell, Partner & Trial Attorney · Last reviewed
Law Offices of Solov & Teitell, APC · (213) 380-9310
Printed from https://www.solovteitell.com/resources/imr-overturn-tracker/ · Last reviewed