For Treating Physicians

California workers' compensation imposes documentation requirements unlike any other payer, and reports that would be entirely adequate in a group health setting routinely fail here.

This page is a practical reference. It is not marketing, and nothing on it asks you to refer anyone.

Requests for authorization

Treatment requests go through utilization review, which runs on strict deadlines from receipt of the request — shorter where the condition is urgent.

What determines the outcome is rarely the request itself.

Most guideline pathways require a documented trial and failure of conservative care. That documentation is frequently in the chart and not in the request.

And the request should engage the guideline directly — explaining why this patient's presentation fits the pathway — rather than restating the diagnosis.

Note two changes: the MTUS shoulder and hand/wrist guidelines were replaced effective January 2, 2026, and the utilization review regulations were restructured effective April 1, 2026 into §§ 9792.9.1–9792.9.8. A denial or an appeal citing the superseded material is citing something that no longer exists.

Where a UR decision is untimely, made by a physician not competent in the relevant field, improperly served, or fails to address what was actually requested, the defect matters — a procedurally defective UR decision is resolved by a workers' compensation judge rather than through IMR.

Permanent and stationary reports

Four things determine whether the report supports a defensible rating.

Address every body part — including compensable consequences. A body part not addressed in this report contributes nothing, and discovery closes at the mandatory settlement conference under § 5502(d)(3).

State impairment as whole person impairment, with the chapter, table, and method identified. Extremity ratings must be converted — 100% upper extremity is 60% whole person; 100% lower extremity is 40%.

State work restrictions specifically — pounds, hours, positions, frequencies. "Light duty" is not a restriction and produces disputes that consume months.

And describe future medical care — what will be needed and for how long. That paragraph determines whether closing future medical is defensible.

Apportionment — where reports most often fail

Under Escobedo (WCAB en banc), an apportionment opinion must explain how and why a non-industrial factor caused a specific approximate percentage of the permanent disability.

Naming a condition and attaching a percentage is a conclusion, not an opinion, and it is not substantial evidence.

Three points that recur:

Apportionment is to disability, not to pathology — but be careful with Lindh.* City of Petaluma v. WCAB (Lindh) (2018) 29 Cal.App.5th 1175 went the *other way: it allowed apportionment to an asymptomatic pre-existing condition that had never disabled the worker, holding that prior disability is no longer a prerequisite. What Lindh still requires is substantial medical evidence that the condition contributed to this disability. Degenerative findings on imaging are near-universal and mostly asymptomatic — pointing at the film is not that evidence.

Medical treatment consequences are not apportionable where the treatment is the sole cause. Under Hikida v. WCAB, where industrial medical treatment itself causes permanent disability — a failed surgery, a post-operative complication — that disability is industrial. But read Hikida with County of Santa Clara v. WCAB (Justice) (2020) 49 Cal.App.5th 605, which held it "precludes apportionment only where the industrial medical treatment is the sole cause of the permanent disability." Where pre-existing pathology also contributes, §§ 4663 and 4664 apportionment still applies — so the reporting physician should address both.

And only physicians determine apportionment. In Nunes (WCAB en banc, 2023), the Board held there is no statutory provision for "vocational apportionment." A vocational expert evaluates employability using the restrictions you provide; they cannot supply or contest apportionment.

When the strict rating does not fit

Under Almaraz/Guzman II, affirmed in Milpitas USD v. WCAB (Guzman) (2010), a physician may depart from a strict application of the AMA Guides where the strict rating does not accurately reflect the impairment — using any chapter, table, or method within the four corners of the Guides.

A defensible opinion does four things:

1. States the strict rating.
2. Explains why it does not accurately capture this patient's impairment.
3. Identifies the alternative method, by chapter and table.
4. Explains why that alternative is more accurate here.

An "obviously inapplicable section" cannot support rebuttal, and a bare assertion that the strict rating "does not reflect the applicant's true impairment" will be rejected. This is where most such opinions fail.

Measurements that are routinely omitted and routinely matter

Shoulder: whether a distal clavicle resection was performed — it carries a fixed value and is frequently buried mid-operative report.

Knee: standing (weight-bearing) x-rays with the cartilage interval measured. Without them the arthritis method cannot be used, and it is worth substantially more than a diagnosis-based estimate.

Interstitial lung disease: DLCO, the most sensitive measure and the one most often omitted from a basic spirometry panel — and VO₂ max on cardiopulmonary exercise testing, which is the route to the higher impairment classes.

Brain injury: formal neuropsychological testing with validity measures. The mental status category generally cannot be rated without it.

CRPS: the Guides require the examiner to personally observe at least eight of eleven objective signs. A treating diagnosis in the records does not satisfy it. Documenting the objective findings at each visit is what preserves the case.

Hearing loss: the rating uses 500, 1,000, 2,000 and 3,000 Hz — the diagnostic 4,000–6,000 Hz notch is not rated, but it is the causation evidence.

And activities of daily living. Several impairment methods are driven entirely by ADL loss — the skin chapter, the brain chapter, and the corticospinal tract axes among them. A detailed ADL history is not a courtesy; it is the measurement.

Interpreters

Where a patient does not proficiently speak or understand English, an interpreter is required and is paid for through the claim — a qualified interpreter at treatment appointments under § 4600(g), and a certified interpreter at medical-legal examinations.

A family member is not a substitute, and an inaccurate history taken through one follows the patient through the entire case.

This page is general information about California workers' compensation reporting requirements, prepared by a law firm. It is not medical advice and it is not a substitute for the AMA Guides, the MTUS, or current DWC regulations.

Questions about a specific report or a specific patient's claim: (213) 380-9310.