Independent Medical Review (IMR) lets a California health plan member ask the state to have independent doctors review a denial based on medical necessity. If the reviewer sides with the member, the plan must follow the decision.
For behavioral health facilities, IMR is often the strongest last step for residential, PHP and IOP denials. It is free to the member, but the member has to start it.
Key points
- IMR is the member's right; the facility can help and advocate.
- Apply within six months of the plan's final decision.
- Independent reviewers overturned most residential, PHP and IOP denials they saw.
DMHC or CDI: which applies
| Plan type | Regulator | Review |
|---|---|---|
| HMOs and most managed care plans (Knox-Keene plans, including Kaiser and most Blue Shield and Anthem Blue Cross products) | Department of Managed Health Care (DMHC) | DMHC IMR |
| Insured PPO and EPO policies (for example Anthem Blue Cross Life and Health) | Department of Insurance (CDI) | CDI IMR |
| Self-funded employer plans | Federal (ERISA) | No state IMR; federal external review |
The member card and plan documents name the plan entity. Many employer plans are self-funded, so check before you plan an IMR.
Who qualifies and when
- The denial, change or delay was based at least in part on medical necessity.
- The member filed a grievance with the plan first. They can go to IMR once the plan upholds the denial or 30 days pass without a decision (3 days for urgent cases).
- The member applies within six months of that point. The state can extend the deadline when circumstances warrant it.
- The member pays no application or processing fee.
Timeline after filing
| Stage | Timeline in the statute |
|---|---|
| Reviewer decision, standard | Within 30 days of receiving the application and documents |
| Reviewer decision, urgent | Within 3 days when there is an imminent and serious threat to health |
| Plan pays for services already given | Within 5 working days of the decision |
These timelines come from the Health and Safety Code. The Insurance Code sets a parallel IMR system for CDI-regulated policies.
How a facility helps a member file
- 1Collect the member's signed authorization at admission. DMHC's Authorized Assistant Form lets the member name someone to help.
- 2Make sure the member's grievance with the plan is on file and dated.
- 3Prepare the clinical packet: records, criteria analysis and a physician letter.
- 4The member, or their authorized assistant, files online with DMHC. DMHC strongly encourages online filing.
- 5Track the decision and confirm the plan pays within 5 working days of an overturn.
California law says the provider may join with or otherwise assist the member, and may advocate on the member's behalf.
What the data shows, 2021 to 2026
| Regulator | Service | Overturned |
|---|---|---|
| DMHC | Residential treatment (n = 1,161) | 79% |
| DMHC | SUD residential | 83% |
| DMHC | PHP and IOP | 87% |
| DMHC | All IMR cases (n = 12,146) | 65% |
| CDI | Behavioral health (n = 121) | 77.7% |
| CDI | Residential treatment (n = 58) | 65.5% |
Recomputed by Sky Gathering RCM from DMHC and CDI case-level data, report years 2021 to 2026 (2026 partial). These are member appeals that reached state external review, so the strongest cases are over-represented. Treat them as an upper bound, not a forecast.
SB 855 and medical necessity criteria
Since January 1, 2021, SB 855 requires state-regulated plans and insurers to base mental health and substance use medical necessity decisions on current generally accepted standards of care. For level of care decisions they must use the most recent criteria from the nonprofit professional association for the specialty, such as The ASAM Criteria for addiction treatment, and may not apply more restrictive criteria.
If a denial relies on a proprietary guideline that is stricter than those criteria, say so in the grievance and the IMR packet.
Not legal advice. This guide is general education, not legal advice. Plan documents, provider contracts and state law can change the rules. Talk to a health care attorney about a specific case.
Frequently asked questions
Can a treatment facility file an IMR?
The member files, or someone the member designates. The facility can assist and advocate, and often prepares the clinical packet.
How long does a California IMR take?
The statute gives reviewers 30 days from receiving the application and documents, or 3 days for urgent cases.
Does IMR apply to self-funded employer plans?
No. Self-funded ERISA plans use federal external review instead of state IMR.
Is the IMR decision binding?
Yes. When the reviewer finds the care medically necessary, the plan must implement the decision, including paying for services already given within 5 working days.
Sources
- Cal. Health & Safety Code § 1374.30 (IMR eligibility and deadlines) (opens in a new tab)
- Cal. Health & Safety Code § 1374.33 (IMR decision timelines) (opens in a new tab)
- Cal. Health & Safety Code § 1374.34 (plan must implement IMR decisions) (opens in a new tab)
- Cal. Health & Safety Code § 1374.721 (SB 855 medical necessity standards) (opens in a new tab)
- Cal. Insurance Code § 10169 (CDI independent medical review) (opens in a new tab)
- Cal. Insurance Code § 10144.52 (SB 855 standards for insurers) (opens in a new tab)
- California DMHC, Independent Medical Review and complaint forms (opens in a new tab)
- California Department of Insurance, Independent Medical Review (opens in a new tab)
- California DMHC, IMR determinations data set (CHHS Open Data), 2021 to 2026, recomputed by Sky Gathering RCM (opens in a new tab)
- California Department of Insurance, Interactive IMR statistics, 2021 to 2026, recomputed by Sky Gathering RCM (opens in a new tab)
- 29 CFR 2590.715-2719, internal claims and appeals and external review (eCFR) (opens in a new tab)
Last reviewed October 2026. Payer rules change; check the source before you file.
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