Treatment denied? Utilization review and IMR, step by step

A treatment denial is not a claim denial

One treatment, one reviewer, one guideline.

Start with the difference, because the letters can look alike. A claim denial says the insurer will not cover the injury at all. A treatment denial says the insurer covers the injury but will not authorize one particular treatment, because a reviewer decided it is not medically necessary under the state’s treatment guidelines.

An accepted claim can produce dozens of treatment denials over its life. Each one is its own small dispute, with its own deadlines, and none of them means your claim is over.

The guideline every reviewer uses. Treatment is measured against the Medical Treatment Utilization Schedule, the MTUS, which incorporates evidence-based guidelines and is presumed correct. That presumption can be rebutted, but only with scientific medical evidence that this patient needs something the guideline does not call for. A request that simply says the treatment is necessary loses to the guideline almost every time.

Medical treatment and the MPN Workers’ comp claim denied?

How a request moves through review

Request, clock, reviewer, notice.

Every utilization review follows the same four steps. Knowing them tells you where to look when something goes wrong.

1. Your doctor files a request. The request goes to the claims administratorClaims administrator / adjuster The person handling your claim for the insurer or self-insured employer. on the state’s Request for AuthorizationRFA Request for Authorization. The form your doctor uses to request treatment. form, the RFA. Since April 1, 2026, secondary treating physicians, such as a specialist you were referred to, may file RFAs themselves, which removes a common source of delay.
2. The clock starts. Counting begins on the first normal business day after the administrator receives a complete request. Where a deadline is measured in hours, it runs from receipt.
3. A reviewer decides. A non-physician may approve a request. Only a licensed physician may modify, delay or deny one, and that physician has to be competent to evaluate the specific issue. The insurer also has to make a peer reviewer reachable by telephone, during California business hours, so your doctor can discuss the request.
4. You are told. The decision has to reach your doctor within 24 hours. A written denial has to reach you within two business days for a request made in advance, and within 24 hours for treatment already under way. That written decision starts your appeal clock.

The deadlines the reviewer has to meet

Hours, business days and calendar days, each with its own rule.

Utilization review runs on hard deadlines, and they are the single most useful thing to check on any denial. A decision that misses them is not just late. It is invalid.

Five business days is the rule. A standard request, whether for treatment in advance or for treatment under way, has to be decided within five business days of receipt of a complete request.

Seventy-two hours when it is urgent. Expedited review applies when the standard timeline would be detrimental to your life or health, or would jeopardize your ability to regain maximum function. It has to be requested and documented by your physician, in writing. It almost never happens on its own: in 2025, 108 of 152,351 IMR determinations statewide were expedited.

Five days, no extension, for a formulary drug. A drug on the MTUS formulary that is not exempt from review gets a hard five-business-day deadline, and the extension rule does not apply to it at all. A reviewer that claims an extension for one has produced an untimely decision on the face of its own letter. If a drug and other treatment are bundled in one request, the standard timeline applies, which is why a drug request is best submitted on its own RFA.

Thirty days for treatment already given. Retrospective review, of care that has already been provided, has 30 days.

Utilization review, every deadline I need surgery and they’re stalling

The first 30 days after an injury

Since April 2026, some early treatment needs no review in advance.

Since April 1, 2026, a rule that had been in the Labor Code since 2018 finally works: for injuries on or after January 1, 2018, treatment given within 30 days of the date of injuryDate of injury For a cumulative or occupational disease claim, the law sets it as when you first suffered disability and knew or should have known it was work-related — not when the wear began. Almost every deadline runs off this. can be authorized without review in advance. It applies only when five conditions are all met.

• The body part or condition has been accepted — A disputed body part is outside the exemption.
• The treatment is consistent with the MTUS — The guideline still governs what qualifies.
• Your doctor files the Doctor’s First Report on time — With the anticipated treatment plan.
• All the treatment planned for those 30 days is in an RFA — The report and the complete RFA both go in within five days of your first visit.
• Bills are submitted within 30 days of service — Or 180 days for emergency treatment.

Even inside those 30 days, some care still needs authorization in advance: drugs that are not exempt under the formulary, non-emergency surgery, psychological and psychiatric treatment, home health care, imaging other than X-rays, medical equipment costing more than $250, electrodiagnostic testing such as EMG and nerve conduction studies, and spinal injections. The 30 days count from the date of injury, not the date you filed a claim or first saw a doctor.

Approved, modified or denied: read for the deadline

A partial approval is a partial denial, on the same clock.

Utilization review can approve a request, modify it or deny it. A modification approves something other than what your doctor asked for: six visits instead of twelve, the injection but not the surgery, physical therapy instead of the MRI, a generic instead of the prescribed drug.

Every modification is a denial of the difference, and it starts the same clock as an outright denial. This is the single most common way an appeal deadline is lost. The letter says “approved,” the worker files it away, and thirty days pass. The right to challenge what was cut is gone.

What the letter has to say. Every review decision has to state what was requested, what was decided, the clinical reason, the guideline it relied on, and how to appeal. Find the appeal instructions and the date before you read anything else.

Old section numbers in the letter. The review regulations were renumbered on April 1, 2026, and some form letters still cite numbers that no longer say what the letter claims. That alone does not make a denial invalid, but it tells you something about how carefully the file is being handled.

They approved part of my treatment They denied my MRI

Two roads after a denial

Timing decides whether a reviewer or a judge answers the medical question.

What happens next depends almost entirely on whether the review was timely.

Check the dates on the letter before anyone argues about the medicine.

If the review was timely: Independent Medical Review. The medical question goes to an independent physician reviewer, working for an organization under contract to the state, who reads the file and decides whether the treatment is medically necessary under the MTUS. The reviewer never examines you, and the reviewer’s identity is confidential by law. The decision binds everyone, and no judge can substitute a different answer on medical necessity. The courts upheld that structure in Stevens v. WCABWCAB Workers’ Compensation Appeals Board. The court system that decides these cases. 23 district offices statewide. in 2015 and in Ramirez v. WCAB in 2017.

If the review was late: a judge. In a 2014 en banc decision known as Dubon II, the Appeals Board held that an untimely utilization review decision is invalid, and that the dispute over medical necessity then goes to a workers’ compensation judge rather than to IMR. Stevens left that rule in place. Timeliness is a legal question the Board still decides, and it is often a winnable one. Every other defect in a review decision is raised inside IMR.

What to check in the letter. Run the letter against this list. Only the first three, the timing, make a denial invalid and send it to a judge; the rest are defects to raise in IMR.

• Was it decided within five business days of a complete request? — That is the deadline for treatment in advance and treatment under way.
• If more time was taken, was written notice given within the five days? — A phone call does not extend the deadline.
• Did it reach your doctor within 24 hours, and you within two business days? — Notice is part of the timing.
• Was the denial made by a physician? — Others may approve; only a physician may modify or deny.
• Was the reviewer competent in the relevant field? — The law requires competence to evaluate the specific issue.
• Could your doctor reach a peer reviewer by phone during business hours? — Its absence is evidence of a defective process, not an automatic defect.
• Were the IMR form and an addressed envelope enclosed? — If not, your appeal clock has not started.
• For a formulary drug, did it claim an extension at all? — None is available.

Filing for IMR, on time

Thirty days, sometimes ten, and an envelope that matters.

If the review was timely, IMR is the only way to challenge the medical decision, and not filing gives up the issue for good. File it even while someone checks the letter for timing.

Thirty days, or ten. You have 30 days from service of the written review decision. If the dispute involves only drugs on the MTUS Drug List, you have 10. Both run from service, not from the day you opened the envelope. The state’s IMR form, revised as of April 1, 2026, now has boxes showing which deadline applies and a field for the mailing date. Before that, nothing on the form warned you.

It costs you nothing. The employer pays for IMR. There is no fee to file.

Send your own records. You are allowed to submit your own documents, on the same deadlines as the claims administrator, and most workers never do. The reviewer decides on paper, so what is in the file is your case: your physician’s rebuttal to the guideline, current imaging, functional findings, and the record of conservative care that failed.

How long it takes. The claims administrator has 15 days to send the records, 12 if it was notified electronically, 10 for a drug-only dispute and 24 hours for an expedited one. A standard determination is due within 30 days, an expedited one within 3 days, and a drug-only one within 5 working days. In practice the reviewers are fast: an average of six to seven days from complete records.

If you win. The employer has to authorize the treatment within 5 working days, and reimburse services already provided within 20 days.

Independent medical review, the honest odds The IMR overturn tracker

The odds, by kind of treatment

Nine denials in ten are upheld. The odds are not the same for every kind of care.

The honest number first. In 2025, IMR issued 152,351 determinations in California workers’ compensation cases and upheld the denial 89.8% of the time. Over the last decade the share overturned has never risen above 12.7% or fallen below 7.2%.

The odds are not the same for every kind of treatment, and that is the useful part.

The two biggest categories. Rehabilitation, meaning physical and occupational therapy, chiropractic and acupuncture, and pharmaceuticals together make up 53.5% of all disputes, and both are overturned about 9% of the time. If your denial is for therapy or medication, the effort usually belongs in the quality of the next request and in checking the timing, not in the IMR filing alone.

Within medications. The spread is wide. Antidepressants were overturned 24.1% of the time and anti-inflammatory drugs 18.9%. Opioids were overturned 6.8% of the time, topical pain relievers 6.0% and muscle relaxants 1.4%.

Who decides. In 2025, 85% of cases were handled by California-licensed reviewers, and occupational medicine physicians decided more than four in ten of all IMRs. Whatever else is said about IMR, it is not slow: 99.99% of standard cases were decided within the 30-day deadline.

After IMR says no

Four things still work after a denial is upheld.

An IMR decision is very hard to overturn. That was the design. It is not the end of your treatment, though, and four things still work.

1. Check the original review for timing. If the utilization review that started it all was late, the dispute belonged in front of a judge in the first place. Raise that as a defect, with the dates, not as a disagreement about the medicine.
2. A new request, with new information. An IMR decision resolves the request that was made. A new request supported by new clinical information is a new request: a failed course of conservative care, a new diagnostic finding, a change in your condition, a specialist’s opinion that answers the guideline directly.
3. Check whether the guideline changed. It has, recently and repeatedly. Four MTUS guidelines were replaced on January 2, 2026, covering the shoulder, the elbow, the hand, wrist and forearm, and traumatic brain injury, and another set took effect on June 1, 2026, covering initial approaches to treatment, chronic pain and eye disorders. A denial resting on a superseded guideline is resting on something that no longer exists.
4. The network’s own review. If the real dispute is about which doctor’s opinion governs, the medical provider networkMPN Medical Provider Network. Your employer’s list of physicians. After the first visit you may switch within it without permission. has a separate process: a second opinion, a third opinion, then the network’s own independent medical review. Where that reviewer agrees with you, you may get the disputed treatment from a physician of your choice, inside or outside the network, and the employer pays.

Appealing the decision itself. You can appeal an IMR decision to the Appeals Board within 30 days, by verified appeal, but only on five narrow grounds, and a disagreement about the medicine is not one of them. The one realistic ground is a plainly mistaken finding of fact that anyone could see from the record, such as a reviewer who says documentation is missing when it is in the file. Even a successful appeal produces a second IMR, not an order for treatment.

IMR upheld the denial Medical provider networks

While you wait

Keep the record, and keep treating if you safely can.

A denial of authorization is not a medical instruction. If you can safely keep treating, do: a gap in treatment is used against you, on causation, on credibility and on the permanent disabilityPD Permanent Disability. Compensation for lasting impairment. A different and much lower weekly rate — 2026 maximum $290/week. rating.

If you are thinking of paying yourself. Treatment you pay for yourself is sometimes reimbursable, where the employer neglected or refused to provide care, but it is fact-specific and carries real risk. Ask before you spend.

If the wait made you worse. Write down what the denial cost you: worse symptoms, lost function, a condition that deteriorated while you waited. A documented decline during a wrongful delay is evidence about your permanent disability, not just a grievance. A treatment authorization that was unreasonably delayed or refused can also support a penalty of up to 25% or up to $10,000, whichever is less.

A file to keep for every denial

Eight lines that answer most questions about a denial.

Each denial is its own small case. Keep one page for each, with the paper behind it.

• The denial letter and its envelope — The service date, and the date it arrived.
• What was asked for and what was decided — Including any part that was modified away.
• Whether the IMR form and an addressed envelope were enclosed — If not, write that down.
• The deadline that applies — 30 days from service, or 10 if the dispute is only about listed drugs.
• The date your doctor’s request was received — From the RFA, the fax confirmation or the letter itself.
• Your IMR filing — The date, a copy, and every document you sent with it.
• Your doctor’s next request — What changed, and the guideline it answers.
• What the wait has cost you — Symptoms, function, missed work, with dates.