Who Pays for Your Medical Treatment in a California Workers Comp Claim?

By Ashley Herrin Crane, Esq., California workers compensation attorney (CA Bar #326337, admitted 2019), Cohen and Associates, San Diego. Last updated 2026-05-18.

In a California workers compensation claim, your employer’s workers comp insurance carrier pays for all medical treatment that is reasonably required to cure or relieve the effects of your work injury. You owe nothing out of pocket. No co-pays, no deductibles, no balance bills. This obligation is set by California Labor Code Section 4600, and it begins the moment your employer learns about your injury, even before the claim is formally accepted.

That is the simple version. The more useful version is what actually happens when you walk into an emergency room, when surgery is recommended, and when the carrier denies a treatment request.

The First Day: Who Pays at the ER

You hurt yourself at work and your supervisor sends you to the nearest emergency room. The hospital is going to ask for insurance information. Tell them clearly:

• This is a work injury.
• Your employer is [name] and the workers comp carrier is [if you know it, otherwise the employer’s name].
• You are not using private health insurance.

Under California Labor Code Section 5402(c), the carrier must authorize up to $10,000 in medical treatment within one working day of receiving notice of the injury, even while it investigates the claim. The ER visit, imaging, and any initial treatment fall under that pre-acceptance authorization.

If the hospital bills you directly anyway, do not pay it. Send a copy of the bill to the workers comp carrier and to the claims adjuster. If the bill keeps coming, an attorney can shut it down with one letter under Labor Code Section 3751, which makes it illegal for a medical provider to balance-bill a worker for industrial treatment.

After the First Visit: The Medical Provider Network

Once the carrier is involved, you are usually directed to its Medical Provider Network, or MPN. The MPN is a list of doctors approved by the carrier to treat injured workers. California requires that the MPN include enough physicians within a reasonable distance of your home or workplace.

A few things to know:

1. You can change MPN doctors. Under 8 California Code of Regulations Section 9767.6, you have the right to change your treating doctor within the MPN at least once without dispute.
2. If you pre-designated a personal physician in writing before your injury, you can go to that doctor instead. The pre-designation form (DWC Form 9783) must have been on file with your employer before the injury date.
3. If the MPN does not have a specialist you need within a reasonable distance, you may be able to treat outside the network.

For the first 30 days of an accepted claim, you generally have to use an MPN doctor. After that, you have somewhat more flexibility, especially if treatment is not working.

Who Decides What Treatment You Get: Utilization Review

This is where things get frustrating. Your doctor writes a Request for Authorization (RFA) for an MRI, physical therapy, surgery, or a medication. The RFA goes to the carrier’s Utilization Review (UR) unit. Under California Labor Code Section 4610, UR has five working days to approve, modify, or deny the request (24 hours for expedited urgent requests).

UR decisions are made based on the California Medical Treatment Utilization Schedule (MTUS), published by the California Division of Workers’ Compensation. MTUS is the official evidence-based treatment guideline for California workers comp.

If UR denies the treatment, you have 30 days to file for Independent Medical Review (IMR). IMR is run by an independent organization and reviews the medical record against MTUS. The IMR decision is binding except in narrow circumstances. The timeline for IMR is roughly 30 to 45 days.

What Workers Comp Pays For

Under Labor Code Section 4600, California workers comp pays for:

• Doctor visits, including specialists.
• Hospital stays, surgery, and anesthesia.
• Prescription medications.
• Diagnostic imaging (X-ray, MRI, CT, EMG).
• Physical therapy and chiropractic care (capped at 24 visits combined for most injuries).
• Durable medical equipment (braces, walkers, TENS units).
• Medical-legal evaluations (QME and AME exams).
• Mileage reimbursement to and from approved appointments.

The mileage rate matches the IRS standard mileage rate. Keep a log.

What Workers Comp Will Not Pay

A few things are commonly not covered:

• Treatment for non-industrial conditions. If you have diabetes and a work back injury, workers comp pays for the back, not the diabetes.
• Experimental treatment outside MTUS.
• Most home modifications, except in catastrophic cases.
• Lost wages, which are paid separately as temporary or permanent disability benefits, not as “medical.”

Cosmetic treatment for injuries that left scars can sometimes be covered if the scar is industrial and the treatment is medically supported.

What If the Carrier Denies the Entire Claim?

If your DWC-1 is denied outright, the medical treatment obligation does not necessarily stop. The pre-acceptance $10,000 authorization stays in place until you receive a written denial.

After denial, your options are:

• Treat under private health insurance and put the carrier on notice that you intend to pursue reimbursement.
• Find a doctor willing to treat on a lien against the case. Some California physicians and clinics will treat injured workers and wait for settlement to be paid.
• File an Application for Adjudication of Claim and litigate the denial at the Workers’ Compensation Appeals Board.

If you win at the WCAB, the carrier becomes liable for all reasonable and necessary treatment retroactive to the date of injury, plus statutory penalties for unreasonable denial.

Hospital Liens and Balance Bills

If a hospital bills you after a clearly industrial injury, that bill is on the carrier under Labor Code Section 3751. You do not need to pay it. The hospital can file a lien in the workers comp case and recover from the carrier directly.

If the hospital reports the bill to your credit, ask for a formal dispute in writing. California law treats balance billing of injured workers as a misdemeanor when done knowingly. If a collections agency starts calling, send a one-page letter stating that this is a workers comp injury, identifying the employer and carrier, and citing Labor Code Section 3751. Most collectors back off once they realize there is an alternate payor.