FREE TO READ

Everything here is free to read, and nothing here is a claim about your case. Built from California’s published records and modified by us — not official government data. How these numbers were made.

Plain English

The words on a denial letter

Thirteen terms, defined the way this dataset uses them. Four of them change how every number on this site should be read, and those are listed first.

The four that change a number

read these four first

Every term

Independent Medical Review (IMR)

California's external review: when a health plan denies a service as not medically necessary or as experimental, an independent physician who does not work for the plan reviews the decision, and the plan is bound by the result.

The Department of Managed Health Care assigns the case to reviewers with no stake in the plan. It costs the enrollee nothing. If the reviewer does not sustain the denial, the plan is required to provide the service — the review is binding on the plan, not advisory.

Every decision on this site is one of these. The Department has published them since 2001 because Health & Safety Code § 1374.33(g) requires it to, and § 1374.33(h)(1)(K) requires each one to carry a summary of the reasoning — which is the only reason a dataset like this can exist at all.

Overturned

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The independent reviewer did not sustain the plan's denial. In California the plan is then required to provide the service.

The word describes what happened to the denial, not a judgement about the plan, the enrollee or the treatment. A reviewer overturns when the record in front of them supports the service under the standard they are applying.

What it does not mean. An overturn rate of 65.2% does not mean 65.2% of denials are wrong. It means that among denials pursued all the way to independent review, that share ended in the enrollee’s favour. See conditional base rate, which is the whole difference.

Upheld

The independent reviewer sustained the plan's denial.

Drawn on this site in its own colour, at the same weight as an overturn, and never as the leftover space in a bar. 20,245 decisions since 2001 were upheld; a reader who represents plans is looking at their side of the record, and it is a fact rather than a remainder.

Medical necessity review

The larger of California's two review types: the service is an accepted treatment, and the dispute is whether this patient needs it.

The reviewer applies the plan’s definition of medical necessity to the clinical record — documented severity, what has already been tried, whether the level of care matches the presentation. These are decided against the patient in front of the reviewer, which is why the same treatment can be overturned in one case and upheld in another without either decision being inconsistent.

Experimental or investigational review

The other review type: the dispute is whether the treatment is established enough to be a covered benefit at all.

The question shifts from the patient to the evidence base, and the reviewer weighs published literature, regulatory status and specialty-society guidance. It is the branch where a named authority — a compendium, a society guideline, an FDA label — most often carries the decision, which is why what reviewers cite is a page of its own. Some of these are decided by a panel of three reviewers, and a split panel publishes each opinion.

Expedited review

The urgent track, decided in days rather than weeks, for cases where waiting would seriously jeopardise the enrollee's health.

The Department decides whether a case qualifies. It is worth asking about: expedited cases resolve in a fraction of the standard time, at no extra cost, and the outcome split differs between the two tracks because the mix of cases differs. Ask the DMHC Help Center — it is free, and it is the authority on whether a specific case qualifies.

Grievance (internal appeal)

The plan's own appeal process, which normally has to be completed — or given 30 days to answer — before an independent review can be requested.

Independent review sits after this step, which is a large part of why the population this dataset describes is so selected. Deadlines and exceptions change; the DMHC Help Center will tell you where a specific case stands, at no charge, and will file the independent review for you.

Utilization review

The process a plan uses to decide whether it will pay for a service — the step that produces a denial in the first place.

Prior authorisation is its most familiar form. Nothing in this dataset describes utilization review itself: these are decisions about denials that were already issued and then contested to the end. The published record does not reliably state the plan’s reasoning, only the ground on which the reviewer resolved the dispute — a distinction the methodology takes seriously, because coding one as the other would be inventing the plan’s side of the argument.

Self-funded plan (ERISA)

CHANGES A NUMBER

An employer plan that pays claims from its own funds. Its external appeals go to a federal process that publishes no decisions, so nobody in the country can describe them.

Roughly half of Americans with employer coverage are in one, and the insurance company’s name on the card is usually just the administrator. These appeals go to a process run for the Department of Health and Human Services which publishes neither decisions nor outcome statistics.

This is the single largest limit on everything here, and it is not a limit of this dataset — it is a limit of what anyone publishes. Human resources or the plan documents will say which kind a plan is. See coverage.

Conditional base rate

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A rate computed over decisions that reached independent review — not over all denials, which nobody publishes.

External review is the end of a long funnel: fewer than 1% of denials are appealed internally at all, and only a fraction of those go further. Every figure on this site is conditional on a denial having survived that funnel.

That makes the population selected and it makes it informative. It does not make it a census, and a number from here should always be read with the condition attached — “among denials taken to independent review”, not “of denials”.

The n=30 floor

CHANGES A NUMBER

No percentage is published for any class holding fewer than 30 decisions. The matched decisions are still shown; the percentage is not.

Below about thirty cases a percentage moves several points when a single decision changes, and it reads as precision it does not have. Where you see a dash instead of a rate, the class exists and the count is real — the explorer will still show it — and no rate is claimed. This is a rule applied before the numbers were seen, not a judgement about which ones looked unreliable afterwards.

De-identified

The published record carries no patient name and no health plan name — the plan's name is removed by statute before publication, not by us.

Health & Safety Code § 1374.33(g) commands the removal of names before these decisions are published, so a per-plan comparison cannot be built from this source by anyone. Nothing on this site restores an identity, links a decision to any other record, or quotes a case narrative — the narratives stay in the build database and never reach the deployment. If you are looking for your own case here, it is not findable, and that is the intended design of the published file.

Data as of

The date California last published the file a page was built from — the Department's date, not the date we downloaded it.

Every page here is stamped 2026-09-04. Showing our capture date instead would imply the data is current as of then; it is current as of whenever the Department last published, which is a different and sometimes much older date.

Nothing here is a substitute for the Help Center. The DMHC Help Center — 1-888-466-2219, dmhc.ca.gov — files an Independent Medical Review at no cost, and it is the same review this dataset describes. You do not need us, a lawyer, or any paid service to reach it.