California Workers' Compensation Medical Care — §4600 Right to Treatment, MPN, Utilization Review, and IMR Appeal

How does the California §4600 right to medical treatment work?

California §4600 owes all medical treatment reasonably required to cure or relieve, physician, hospital, surgery, medication, therapy, prosthetics, and mileage.

California Labor Code §4600 defines the employer's medical-care duty broadly. "All medical treatment reasonably required to cure or relieve the effects of the injury" includes physician visits, hospital care, surgery, prescription medication, physical therapy, occupational therapy, chiropractic (capped under §4604.5), durable medical equipment, prosthetics, mileage to treatment, and interpreter services under California Labor Code §5811. The duty applies through the lifetime of the claim, not just during temporary disability. Future medical is a separate award category in PD-only or denied-rated cases.

California Labor Code §4604.5 caps chiropractic, physical therapy, and occupational therapy at 24 visits each per industrial injury. The predesignation framework under §4600 allows a worker who designates a personal physician in writing before the injury to treat with that physician outside the MPN. California Labor Code §4603.2 sets the medical billing framework. California Labor Code §4603.6 covers IBR (Independent Bill Review) for billing disputes between providers and insurers.

How does the California §4616 Medical Provider Network (MPN) work?

A California MPN is a closed network of approved physicians the worker treats within after the first visit, unless the worker pre-designated a personal physician.

California Labor Code §4616 authorizes employers to use Medical Provider Networks. An MPN is a closed panel of physicians, hospitals, and ancillary providers approved by the Administrative Director under California Labor Code §4616.3. After the worker's first physician visit, treatment must be within the MPN unless the worker pre-designated a personal physician under the California Labor Code §4600 predesignation provisions. The MPN must include at least three physicians per specialty within a reasonable geographic area. The worker has the right to a second opinion within the MPN and a third opinion if the second disagrees.

MPN disputes are common: out-of-MPN treatment denied, second-opinion disputes, MPN composition challenges. The California MPN framework page explains the rules. The MPN vs predesignation comparison page explains the trade-offs. The MPN second-opinion case study illustrates the second-opinion strategy.

How does California §4610 utilization review work?

California §4610 utilization review subjects every treatment recommendation to medical-necessity review by a licensed physician hired by the insurer.

California Labor Code §4610 requires every California insurer to conduct utilization review on requested treatment. The treating physician submits a Request for Authorization (RFA) on DWC Form RFA. The UR reviewer, a licensed physician, applies the Medical Treatment Utilization Schedule (MTUS) under California Labor Code §4604.5 and California Labor Code §4600 to determine medical necessity. UR can be prospective (before treatment), concurrent (during), or retrospective (after). Prospective UR must complete within five business days of receipt; expedited UR within 72 hours when delay would harm the worker.

UR denials must include the specific reason and the underlying clinical guideline. The denial is automatically appealable to Independent Medical Review under California Labor Code §4610.5. Failure to issue UR within the statutory window deems the treatment authorized, the §4610 deadline is the worker's lever. The §4610 UR card explains the framework. The UR denial appeal page explains the IMR appeal.

How does California §4610.5 Independent Medical Review work?

California §4610.5 IMR is the binding appeal route from a UR denial, a Maximus reviewer decides the medical-necessity dispute on the existing UR record.

California Labor Code §4610.5 establishes Independent Medical Review as the binding appeal route from a California Labor Code §4610 UR denial. The worker (or counsel) files the IMR application within 30 days of the UR denial. The IMR is administered by Maximus Federal Services under contract with the Division of Workers' Compensation. A medical reviewer with specialty matching the disputed treatment reviews the existing UR record, the treating physician's report, the medical records, and the MTUS guideline applied. The IMR decision is binding and not appealable except for fraud, conflict of interest, or non-medical defect.

IMR success rates favor the insurer when the treating physician's report does not engage with the MTUS guideline cited in the denial. A strong IMR submission addresses the specific clinical reasoning in the UR denial point-by-point. The IMR appeal page explains the procedural framework. The IMR appeal case study illustrates a successful reversal.

How does the California QME / AME process under §4062 work?

A California QME or AME is the medical-legal evaluator who decides disputed medical-legal issues, causation, permanent disability, apportionment, work restrictions.

California Labor Code §4062 authorizes objection to a treating physician's medical-legal determination. California Labor Code §4062.1 sets the unrepresented-worker QME panel selection. California Labor Code §4062.2 sets the represented-worker QME panel selection, a three-physician panel is issued by the Medical Unit, and each party strikes one within 10 days. The remaining physician is the QME. An Agreed Medical Evaluator (AME) is a physician both parties stipulate to instead of QME panel selection. The QME or AME issues a comprehensive medical-legal report addressing causation, work restrictions, permanent disability rating under the AMA Guides, and apportionment under California Labor Code §4663.

The QME/AME report is the most important medical document in any disputed claim. The QME vs AME page explains the trade-offs. The §4062.2 panel-strike card explains the strike strategy. The QME panel-strike case study illustrates timing-based strategy.

How does California predesignation of a personal physician work?

California predesignation provisions allow a worker to designate a personal physician, treating outside the MPN from the first visit forward.

The California Labor Code §4600 predesignation framework (per California Division of Workers' Compensation regulation 9780) allows a worker to designate a personal physician in writing before the date of injury. The written designation must identify the physician, be signed and dated, and be on file with the employer. When properly predesignated, the worker treats with the personal physician from the first post-injury visit forward, outside the MPN. Predesignation requires the personal physician to be the worker's regular treating physician for non-occupational conditions, agree in writing to treat the worker for industrial injuries, and have the worker's medical records.

Predesignation is the most powerful pre-injury option for California workers who want to avoid MPN constraints. Without predesignation, the first visit is to the employer-designated provider; thereafter the worker is in the MPN unless the worker fires the MPN treater (changes within the MPN) or the MPN is challenged for inadequacy. The predesignation rules under §4600 card explains the requirements.