How to File a Workers' Comp Claim in California

Workers' compensation runs on its own statute, its own forms, and its own deadlines. None of it resembles a property or auto claim, and the single most common mistake — on both sides — is treating a conversation with a supervisor as if it were a filed claim.

It isn't. Notice and a claim are two different things. This guide covers the sequence from injury to benefits, for the injured worker and for the employer, with the deadlines that actually control the outcome.

For the immediate first-72-hours actions, start with what to do after a workplace injury. This guide picks up at the paperwork.

The seven-step sequence

Step 1 — Report the injury (employee: within 30 days; in practice, today)

Labor Code §5400 requires notice to the employer within 30 days of the injury. For cumulative trauma or occupational illness, the period generally runs from when the worker knew or should have known the condition was work-related.

Report in writing. An email or a text creates a dated record; a hallway conversation does not.

Step 2 — Get the DWC-1 (employer: within one working day)

Under Labor Code §5401, the employer must give the employee a DWC-1 claim form within one working day of learning about the injury, and must return a completed copy within one working day of receiving it back.

The DWC-1 has two halves. The employee completes the top: name, address, date and time of injury, where it happened, and the parts of the body affected. Be specific and be inclusive — list every body part involved, because parts left off can be argued over later. Sign and date it. Keep a copy before handing it back.

The employer completes the bottom and forwards it to the claims administrator.

Step 3 — Filing opens the claim

The claim is legally opened when the completed DWC-1 is filed with the employer. Everything downstream — the treatment authorisation, the 90-day clock, the benefit obligations — runs from that.

If no one gives you a form, request one in writing, keep the request, and get the form from the Division of Workers' Compensation directly.

Step 4 — Treatment begins immediately, not after approval

Within one working day of receiving the claim form, the employer must authorise up to $10,000 in appropriate medical treatment while the claim is investigated. You are not supposed to wait for a decision to be treated.

Treatment normally runs through the employer's medical provider network (MPN) unless you validly predesignated a personal physician in writing before the injury. Under Labor Code §4600, medical treatment reasonably required to cure or relieve the effects of the injury is provided at no cost to the employee — no deductibles, no copays.

Treatment requests go through utilisation review, and a denial can be appealed to independent medical review. Those deadlines are short. Read every letter the day it arrives.

Step 5 — The 90-day decision

Under Labor Code §5402(b), if the claim is not denied within 90 days of the DWC-1 being filed with the employer, the injury is presumed compensable, and that presumption can generally only be rebutted by evidence discovered after the 90-day period.

This is the most important deadline in California workers' compensation, and it runs against the employer and the carrier — which is precisely why prompt reporting by the employer matters so much.

Step 6 — Benefits begin

Benefit	What it does	Key rule
Medical treatment	Reasonably required care to cure or relieve	No cost to the employee (Lab. Code §4600)
Temporary disability (TD)	Wage replacement while unable to work	Generally two-thirds of average weekly wages, subject to statutory minimums and maximums; a three-day waiting period applies unless hospitalised or off more than 14 days (§4652–4653)
Permanent disability (PD)	Compensation for lasting impairment	Rated after the condition reaches maximum medical improvement
Supplemental job displacement	Retraining voucher	Where the employer doesn't offer suitable regular, modified, or alternative work
Death benefits	To dependants	Statutory schedule

Late payments carry a penalty. Under §4650, TD or PD not paid within the statutory period is increased by 10%, and §5814 allows further penalties for unreasonable delay.

Step 7 — If there's a dispute

• Free state help first. DWC Information & Assistance officers help injured workers at no cost: 1-800-736-7401. Use this before assuming you need a lawyer.

• QME/AME. Disputes over medical issues are resolved through a qualified medical evaluator (or an agreed medical evaluator if both sides agree on one).

• Application for adjudication. Filed with the Workers' Compensation Appeals Board.

• The one-year deadline. Under Labor Code §5405, the application generally must be filed within one year of the date of injury, or the last date benefits were provided, or the last date of furnished medical treatment. Reporting the injury does not protect this deadline.

Employer with an open claim you're not getting answers on? That's what an agent is for. (209) 524-6366 Modesto · (530) 221-3031 Redding · Claims Center

The employer's side of the same seven steps

Step	Obligation	Deadline
1	Provide the DWC-1 claim form	One working day from notice
2	Report the claim to your carrier / claims administrator	Same day — best practice
3	Authorise up to $10,000 in treatment	One working day from receiving the claim form
4	File the employer's report (Form 5020)	Five days for any injury beyond first aid
5	Report serious injury to Cal/OSHA	Immediately
6	Provide benefit notices and MPN information	Per DWC notice requirements
7	Accept or deny	90 days, or the claim is presumed compensable

Three things that cost employers money and are entirely within their control:

Delay. Every day between injury and report raises the ultimate cost of the claim. Prompt reporting is the highest-return administrative habit in workers' compensation.

No modified duty. Getting an injured worker back on transitional duty within their written restrictions shortens the claim, lowers indemnity cost, and improves recovery. Make the offer in writing.

Retaliation, or anything that looks like it. Labor Code §132a penalises discrimination against an employee for filing a claim. Discipline for a documented, unrelated reason is lawful; discipline that lands the week after a claim is filed will be scrutinised.

What this does to your experience modification factor

Your ex-mod is calculated from your claims history relative to expected losses for your class codes and payroll, and it weights frequency more heavily than severity. Several small claims move a mod more than one moderate one.

Practically: report everything promptly, get medical care immediately, use modified duty, close claims rather than letting them sit open with high reserves, and audit your open-claim reserves before your ex-mod is calculated. An inflated reserve on a claim that's effectively resolved will sit on your mod for three years.

If your mod moved and no one has explained why, that's a renewal conversation to have early. See switching workers' comp carriers.

Common mistakes on both sides

Employees: waiting to report; not listing every affected body part on the DWC-1; not keeping a copy; missing utilisation review appeal deadlines; assuming the one-year filing deadline is handled automatically.

Employers: not giving out the DWC-1; assuming a minor injury doesn't need reporting; letting the 90 days run; no return-to-work programme; no documented investigation; not carrying coverage at all — which in California carries penalties including stop orders and personal liability, and removes the exclusive-remedy protection that keeps the injured worker from suing you directly.

Whether you need coverage at all is answered in do I need workers' comp insurance in California.

FAQs

How do I file a workers' comp claim in California?

Report the injury to your employer in writing, complete the employee section of the DWC-1 claim form your employer must provide within one working day, keep a copy, and return it. Filing the DWC-1 opens the claim.

How long do I have to file a workers' comp claim in California?

Notice to the employer within 30 days (Lab. Code §5400); an application for adjudication generally within one year of the injury, the last benefit paid, or the last medical treatment (§5405).

What is the 90-day rule in California workers' comp?

If the claim is not denied within 90 days of the DWC-1 being filed with the employer, the injury is presumed compensable (§5402(b)).

Do I get paid while I'm off work?

Temporary disability generally pays about two-thirds of average weekly wages, subject to statutory minimums and maximums, after a three-day waiting period that's waived if you're hospitalised or off more than 14 days.

Can I be fired for filing a workers' comp claim?

Labor Code §132a prohibits discrimination against an employee for filing or intending to file a claim.

Do I need a lawyer?

Not always. Start with the free DWC Information & Assistance service at 1-800-736-7401.

A workers' comp claim is a process with deadlines. We know them.

TSM Insurance builds and services workers' compensation programmes for Central Valley employers — including the claim handling, the return-to-work conversation, and the ex-mod review before renewal.

Modesto (209) 524-6366 · Redding (530) 221-3031 · Talk to a TSM advisor