How Does an IMR Appeal Work for Denied Treatment in California?

How IMR works after a treatment decision

IMR is a records-based review of an eligible UR medical-necessity decision. Start by saving the complete decision, IMR notice, and proof of service.

Utilization Review, often called UR, may approve, modify, or deny a treating physician's request for care. When the written UR decision denies or modifies treatment based on medical necessity, Labor Code section 4610.5 can provide the IMR process. IMR is different from a hearing about the whole claim.

Read the complete notice. An eligible request generally must be filed within 30 days after service of the written UR decision. The period is 10 days only if the decision solely denies or modifies a request for a drug on the MTUS Drug List. A separate dispute about liability or missing required notice can affect when the period begins under Rule 9792.10.1.

The treatment-denial guide explains how to preserve a denial letter and distinguish a treatment issue from a whole-claim dispute.

Keep the three IMR clocks separate

The request clock is not the same as the time for the independent review organization to issue a determination. A regular determination is binding when issued. A later petition is not a second medical review just because a party disagrees with the medical conclusion.

What records are submitted?

Both sides have record-submission duties and opportunities after IMR assignment. Keep a copy of what is sent and of any document list you receive.

After assignment, the claims administrator must submit the records and information required by Rule 9792.10.5, including relevant physician reports, materials submitted in support of the treatment request, information used in making the UR decision, and its response to issues raised in the IMR application. It must also notify the employee or representative of the documents submitted and provide copies of documents not previously provided, subject to the rule's limits.

The employee, representative, treating physician, or another eligible party may submit the treating physician's recommendation and reasonable information supporting medical necessity within the rule's applicable submission period. Newly developed or discovered relevant medical records held by either side must be forwarded promptly, with the required concurrent service. The independent review organization may request additional appropriate information from a party.

Useful records often include the Request for Authorization, the written UR decision, treating notes, test results, therapy records, medication history, and a short timeline. The right records depend on the reason given in the decision. The Labor Code 4610.5 explainer covers the statutory role of IMR.

What can happen after the determination?

The determination states whether disputed treatment is medically necessary. A petition to the WCAB is limited by statute and procedure.

Rule 9792.10.6 says the independent review organization issues a determination based on the submitted materials. If the claims administrator fails to provide required documentation, the rule still describes what information may be used and says no determination may rest only on the UR decision. The determination is binding on the parties.

Labor Code section 4610.6 permits limited review for grounds stated in the statute, including action without or in excess of powers, fraud, a material conflict of interest prohibited by the statute, specified discriminatory bias, or a plainly erroneous factual finding involving ordinary knowledge rather than expert opinion. The statute requires clear and convincing evidence. A petition must state its factual and legal grounds. Rule 10575 supplies the separate 30-day period after service, identifies required petition information, and includes a deferral rule when treatment liability was disputed for another reason at the time of the determination.

A later treatment request can depend on changed medical facts and the treating physician's assessment. It is not possible to predict an IMR outcome from a diagnosis or a general description of the request.

The current official application also explains mailing-related additions to filing time. Check the form, service method, and instructions before calculating the deadline for a specific notice.

Prepare for a focused conversation

Save the complete UR decision, IMR notice, proof of service, Request for Authorization, recent treating records, and a short timeline. The California workers' compensation consultation checklist can help organize the file.

Yazdchi Law is based in Palmdale. Call (661) 273-1780 or use the contact form to ask whether the firm can assess a California workers' compensation matter. Each matter is assessed individually.

Official IMR sources

• IMR request rules
• Medical-record submissions
• Determination standards and timing
• Petition after an IMR determination
• Current official DWC Form IMR (PDF)