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Utilization review and independent medical review (IMR)

By the CalCompGuide editorial team · Last updated November 2026 · How we write and check guides

Short answer

Every treatment your doctor requests goes through utilization review (UR), where the insurer's reviewing doctor checks it against treatment guidelines. If UR denies or modifies the request, you can ask for independent medical review (IMR) by the state's contractor. You must file the IMR application within 30 days after the UR decision is served (only 10 days if the denial is solely for a drug on the MTUS drug list). Filing IMR costs you nothing.

How utilization review works

Your doctor sends a Request for Authorization (RFA). The claims administrator's UR process must decide it within set times, generally 5 business days from receipt of the request (up to 14 days if more information is needed), and within 72 hours for urgent requests (LC §4610). Only a licensed physician can deny or modify a request for medical reasons. The decision letter must explain the reasons and the guideline used, and it comes with an IMR application.

Filing for IMR

  1. Find the Application for Independent Medical Review (DWC Form IMR) included with the UR denial. It's also on the DWC IMR page.
  2. Sign it and send it, with a copy of the UR decision, to the IMR contractor by mail, fax or electronically, as listed on the form.
  3. Send a copy of the signed form (without the decision letter) to the claims administrator.
  4. Deadline: 30 days from service of the UR decision; 10 days if it only concerns an MTUS drug list medication (8 CCR §9792.10.1).

Your treating doctor can help by sending supporting records and explaining why the treatment is needed. Ask them to.

What IMR decides, and what it doesn't

IMR decides only whether the requested treatment is medically necessary under the guidelines. Its decision is binding, with a narrow appeal to the WCAB (for example fraud, conflict of interest or a plainly mistaken fact) that must be filed within 30 days. If the insurer denies treatment for a reason other than medical necessity, such as claiming the body part isn't part of the injury, that dispute goes to the WCAB, not IMR.

Practical tips

  • Write the date you received each UR letter on the envelope. Service date matters.
  • Don't wait for a second UR on the same request; file IMR.
  • If the treatment is urgent and the denial seems to violate timelines, a workers' comp attorney or the DWC I&A unit can tell you about expedited options.
  • While a treatment is disputed, you can still get other approved care.

Key deadlines

  • UR decision: generally 5 business days (max 14) after the request; 72 hours if urgent.
  • IMR application: 30 days after the UR decision is served (10 days for MTUS-list drugs only).
  • Appeal of an IMR decision to the WCAB: 30 days.

Sources

Official sources checked November 2026. Laws and rates change; check the source for the latest version.

Related guides

This guide is general information, not legal advice. Every case is different. For free help from the state, call the DWC Information & Assistance unit at 1-800-736-7401.