What dispute deadlines should providers track in California?

Initial Medical Bill Submission: 12 months from date of service; Payer Explanation of Review (EOR): 45 days for paper bills; 15 days for compliant e-bills; Request for Second Review (SBR-1): 90 calendar days from service of initial EOR. Verify the trigger date, current agency notices, and any extension before acting.

Which agencies administer these rules in California?

The guide identifies California Division of Workers' Compensation (DWC), Workers' Compensation Appeals Board (WCAB). The correct agency depends on the plan and claim jurisdiction.

Workers' Compensation Medical Billing State Guides

California Workers' Compensation Medical Billing Guide

California workers' compensation medical treatment and billing are administered by the Department of Industrial Relations Division of Workers' Compensation (DWC). Disputes over medical billing amounts are strictly resolved through Second Review and Independent Bill Review (IBR) pursuant to Labor Code Section 4603.6.

Accountability & Review

Reviewed by Millennova Legal Operational Integrity Team, Senior Audit and Arbitration Analysts

Last Reviewed

2026-03-05

Plain-language overview

Statutory no-fault workers' compensation system with employer Medical Provider Networks (MPNs) and standardized utilization review.

Medical fee schedule and reimbursement rules

Name

Official Medical Fee Schedule (OMFS) - 8 CCR §§ 9789.10 - 9789.111

Structure

RBRVS-based fee schedule updated annually with California-specific conversion factors for physician services, outpatient facilities, and inpatient hospitals.

Electronic Billing

Mandatory e-billing compliance under California Labor Code Section 4603.4 and 8 CCR §§ 9792.5.0 - 9792.5.3

Preauthorization and utilization review

Protocol

Utilization Review (UR) governed by Labor Code § 4610. Providers submit DWC Form RFA (Request for Authorization).

Deadlines

Prospective review decision must be communicated to the treating physician within 5 business days of receipt of complete clinical records.

Dispute Mechanism

Independent Medical Review (IMR) through Maximus Federal Services (Labor Code § 4610.5)

Billing and appeal procedure

Timely Filing

12 months from the date of service (Labor Code § 4603.2(b)(2))

Second Review

Mandatory prerequisite before IBR. Must be filed within 90 days of receipt of Explanation of Review (EOR) on DWC Form SBR-1.

Independent Bill Review

Governed by Labor Code § 4603.6 and 8 CCR § 9792.5.4. Must be filed within 30 days of receipt of second review EOR with designated contractor (Maximus).

Wcab Role

WCAB retains jurisdiction only over threshold legal liability issues (e.g., employment relationship, injury arising out of employment), not fee schedule calculations.

Claim and dispute deadlines

Deadlines can depend on the trigger event and may be affected by agency relief notices. Confirm the live rule before filing.

Event	Timeframe
Initial Medical Bill Submission	12 months from date of service
Payer Explanation of Review (EOR)	45 days for paper bills; 15 days for compliant e-bills
Request for Second Review (SBR-1)	90 calendar days from service of initial EOR
Payer Response to Second Review	14 calendar days from receipt
IBR Application Filing	30 calendar days from service of Second Review EOR

Documentation checklist

Complete CMS-1500 / UB-04 form with standard WC modifiers
Treating physician Doctor's First Report of Occupational Injury (Form 5021) or PR-2/PR-4 progress reports
Approved Request for Authorization (RFA) with UR approval letter where applicable
Itemized statement of contested codes, OMFS fee calculations, and ground-rule justifications
Copy of original EOR and Second Review EOR

Responsible agencies

California Division of Workers' Compensation (DWC)Administration of State Workers' Compensation Laws
Workers' Compensation Appeals Board (WCAB)Judicial review of threshold compensation disputes

Primary legal and regulatory sources

California Labor Code Division 4 (Workers' Compensation and Insurance)California State Legislature · 2024
California Code of Regulations Title 8, Division 1, Chapter 4.5 (Division of Workers' Compensation)California DWC · 2025

This operational reference is educational, is not legal advice, and does not create an attorney-client relationship.

Common questions

What rules govern workers' compensation medical billing state guides in California?: California workers' compensation medical treatment and billing are administered by the Department of Industrial Relations Division of Workers' Compensation (DWC). Disputes over medical billing amounts are strictly resolved through Second Review and Independent Bill Review (IBR) pursuant to Labor Code Section 4603.6.
What dispute deadlines should providers track in California?: Initial Medical Bill Submission: 12 months from date of service; Payer Explanation of Review (EOR): 45 days for paper bills; 15 days for compliant e-bills; Request for Second Review (SBR-1): 90 calendar days from service of initial EOR. Verify the trigger date, current agency notices, and any extension before acting.
Which agencies administer these rules in California?: The guide identifies California Division of Workers' Compensation (DWC), Workers' Compensation Appeals Board (WCAB). The correct agency depends on the plan and claim jurisdiction.