California Workers' Compensation Utilization Review and IMR: Provider Guide

Treatment authorization and medical-bill payment disputes are different tracks. Utilization review and independent medical review address whether proposed or rendered treatment is medically necessary. California independent bill review addresses the amount payable after a provider receives an explanation of review and completes the required second-review process. A provider should classify the dispute before selecting a deadline or form.

This guide reflects California Division of Workers' Compensation regulations and guidance available on September 24, 2026. It is written for provider operations and does not determine whether a particular treatment is medically necessary, compensable, exempt from review, or payable.

California authorization workflow at a glance

1. Build a complete request for authorization

Title 8, section 9792.6.1 defines a request for authorization as a written request for a specific course of proposed treatment. Unless the claims administrator accepts another submission under section 9792.9.1, the request must be on DWC Form RFA and completed by the treating physician. DWC reinforced that requirement in a May 14, 2026 notice after the updated utilization-review regulations became operative on April 1, 2026.

For regulatory completeness, the request must identify the employee and requesting provider, identify all recommended treatments with specificity, include documentation created no earlier than 30 days before submission that substantiates the need for treatment, and carry the treating physician's signature. Electronic signatures are permitted by agreement of the parties.

• State each requested treatment separately rather than relying on a general plan-of-care phrase.
• Connect diagnoses, findings, prior treatment, response, functional limitations, and requested services.
• Address applicable Medical Treatment Utilization Schedule criteria and explain any clinically supported variance.
• Use supporting documentation created within the regulation's 30-day window.
• Identify the correct claims-administrator destination and retain the exact transmitted packet.
• Preserve the electronic timestamp, fax report, EDI receipt, certified-mail receipt, or other delivery evidence.

When a narrative report may function as the request

DWC states that a narrative report may serve as a functional equivalent only when the claims administrator voluntarily accepts it and the report satisfies the required content standards. Operationally, the safer default is the prescribed RFA. If a narrative is accepted, the file should document that acceptance and verify that the employee, provider, treatments, recent support, and signature requirements are present.

2. Prove when the request was received

Section 9792.9.1 ties receipt to the transmission method. A fax, email, or EDI submission is generally received when electronically date-stamped. A transmission after 5:30 p.m. Pacific Time is deemed received on the next business day except for expedited or concurrent review. Mail and certified mail have separate receipt rules. These details affect when the utilization-review clock starts.

If a request does not meet the completeness definition, the claims administrator must either accept it as complete and process it or mark it not complete and return it to the requesting physician with reasons no later than five business days after receipt. A returned request should be reviewed against the stated defect instead of simply resent unchanged.

3. Calendar the correct utilization-review deadline

The first day for a business-day period is the first normal business day after receipt of the completed or accepted request. Hour-based requirements are counted from the time of receipt. A provider dashboard should therefore retain both the date and time when the submission method records them.

4. Audit a modification or denial

A decision to modify or deny treatment must be made by a physician reviewer competent to evaluate the clinical issues and acting within the relevant scope of practice. The written decision must identify receipt and decision dates, the requested course of treatment, records reviewed, any approved portion, the clinical reasons, and the medical criteria or guidelines used. It must also include the current IMR application and required dispute information.

• Confirm that every requested service received a clear disposition.
• Compare the records listed as reviewed with the packet actually submitted.
• Identify whether the reason is medical necessity, missing information, or a non-medical liability issue.
• Record the date and method of service of the written decision.
• Route the decision immediately to the injured worker or authorized representative responsible for the IMR election.
• Do not treat a voluntary internal appeal as automatically extending the IMR filing deadline.

The regulations state that failure to obtain advance authorization is not an acceptable basis for refusing coverage of emergency health care used to treat and stabilize an injured worker, although the services may undergo retrospective review. Emergency status and medical necessity still require a documented record.

5. Distinguish who may request IMR

The injured employee, the employee's attorney or qualifying designee, and a provider of emergency medical treatment in the specified retrospective-review situation are eligible filers under section 9792.10.1. The treating physician whose request was denied or modified may join with or assist the employee and may submit supporting documents, but an ordinary treating provider does not independently replace the employee as the IMR applicant.

For most treatment disputes, the IMR application must be filed within 30 days after service of the written UR determination. A dispute involving only a drug listed on the MTUS Drug List uses a 10-day period. The application must use the current DWC Form IMR, include the written denial or modification, and be copied to the claims administrator as required. Other-liability disputes and defective notices can affect when the period begins, but that analysis should be documented rather than assumed.

6. Build the IMR medical record

After assignment, the employee, representative, requesting physician, or another eligible party may submit medical-necessity materials within the regulatory window: generally 15 days after mailed notice, 12 days after electronic notice, 10 days for a drug-only dispute, or 24 hours for expedited review. Documents sent to the independent review organization must be served concurrently as the regulation requires.

1. Start with the exact treatment and rationale stated in the RFA.
2. Address the specific clinical reason and guideline cited in the UR decision.
3. Include the treating physician's recommendation and the records that show present findings and functional need.
4. Explain prior conservative treatment, results, contraindications, and material changes where relevant.
5. For expedited review, include the physician certification and documentation of imminent and serious risk.
6. Create an exhibit list and serve the same evidentiary record on the claims administrator when required.
7. Preserve proof of timely filing and delivery for every submission.

7. Track the IMR determination

The independent review organization generally has 30 days after receiving the application and supporting information to decide a regular dispute, three days for an expedited dispute when treatment has not been provided, and five business days for a drug-only MTUS dispute. The determination addresses medical necessity based on the documentary record and is deemed the Administrative Director's determination and binding on the parties, subject to the limited statutory appeal process.

DWC guidance states that when IMR finds already-rendered treatment medically necessary, the claims administrator must reimburse the provider within 20 days; when treatment has not been provided, authorization must issue within five business days, subject to a preserved non-medical liability dispute or appeal. Record the determination, implementation date, and any separate billing issue rather than assuming the IMR result resolves the amount payable.

Provider quality-control checklist

• Current DWC Form RFA used unless documented acceptance of a compliant narrative exists.
• Employee, requesting physician, and each requested treatment identified precisely.
• Supporting documentation created within 30 days before submission.
• Treating-physician signature and safe transmission method confirmed.
• Receipt, completeness, UR decision, and service dates tracked separately.
• Modification or denial audited for reviewer, rationale, criteria, records, and IMR materials.
• IMR applicant authority and 30-day or 10-day filing period confirmed.
• Medical-necessity evidence served within the assignment-notice deadline.
• Any later payment-amount dispute routed to California's separate bill-review process.

Related Millennova Legal resources

Use Millennova Legal's workers' compensation dispute support and the California workers' compensation state guide for broader jurisdiction context. For a dispute about reimbursement amount rather than medical necessity, use the separate California Independent Bill Review guide. Compare other state payment pathways in the Texas medical-fee dispute guide.

California primary sources