Pre-Existing Conditions and California Workers Comp

What does California law say about old conditions?

California law covers work injuries even when the worker was not in perfect health before the accident or repeated job strain.

A worker does not have to prove a perfect body. Work comp covers injuries that arise from the job. That can be one event, like a fall. It can also be repeated strain over time. An old problem may be part of the story, but it does not erase the work injury.

Medical care is still owed for the work injury under Labor Code 4600. Wage loss may be owed while the doctor keeps the worker off work. Permanent disability may be owed when the condition becomes stable. The insurer cannot reject the whole claim just because an MRI shows age changes.

The hard part often comes later. At maximum medical improvement, the doctor may rate permanent disability. The insurer may ask the QME or AME to split the rating between work causes and non-work causes. That split must be based on evidence.

How does apportionment affect the case?

Apportionment reduces only the permanent disability share assigned to work. It does not erase the injury or the need for treatment.

Labor Code 4663 says apportionment is based on causation. In plain English, the doctor must explain what caused the disability. The doctor must say what share came from work and what share came from other causes. A bare guess is not enough.

Labor Code 4664 also matters. The employer is liable only for the part caused by work. But the employer must still prove the non-work part. A report that says "degeneration" without a clear how and why can be challenged.

The benefit figures belong in the standard tables below. They should not be guessed in prose.

What proof helps defeat unfair apportionment?

The best proof shows the worker was doing the regular job before the injury and had no real limits from the old condition.

Useful proof is often simple. It may include time cards, job reviews, coworker notes, gym records, photos, and a lack of recent treatment. These facts show the worker was active before the job injury. They help separate silent imaging from real disability.

Tell the truth about prior care. Hiding an old claim can hurt the case. A clear timeline is stronger. It lets the doctor see what changed after the work event or after months of job strain.

What should the QME report explain?

A useful QME report names the non-work cause, explains how it caused disability, and gives a reasoned percentage.

A QME or AME report should not stop at labels. It should explain why the old condition caused current limits. It should address symptoms before the injury. It should compare old records with new records. It should explain the work duties that made the body part worse.

If the report skips those steps, the worker can request a supplemental report. The doctor can be deposed. The issue can be tried before the WCAB. Unsupported apportionment is often worth fighting because it can change the final award.

What if I had a prior claim to the same body part?

A prior claim makes the case more detailed, but it does not block a new claim for a new injury or new worsening.

The new case should be built with both files in mind. The prior settlement, old ratings, old work limits, and later job duties all matter. The goal is to show what was already there and what the new job injury added.

A worker may still receive treatment for the new injury. The worker may also receive a rating for the new disability share. The facts decide the split, not the mere fact that an older claim exists.

What records should I gather now?

The best pre-existing condition record is built early, with job proof, medical proof, wage proof, and clear notes about what changed.

Start with the basics. Save old medical records, prior claim papers, pharmacy lists, work reviews, attendance records, and names of people who saw you work full duty. Keep the papers in date order if you can. A simple folder on your phone can help. Take screenshots before messages disappear. Write names with job titles, not just first names.

Medical proof should be clear and practical. Keep every work status slip. Keep every report that lists restrictions. Keep visit summaries and referral notes. If a doctor writes something wrong, ask how to correct it. Small errors can grow into large disputes later.

Wage proof also matters. Save pay stubs, direct deposit records, tip records, time cards, mileage notes, and missed-work calendars. Benefit disputes often turn on dates and wages. A clean record makes the claim easier to explain.

Do not edit records or guess at facts. If you are unsure about a date, say so. A careful timeline is better than a perfect-sounding story that later proves wrong. The goal is to make the record honest, complete, and easy for a judge or doctor to follow.

What mistakes should I avoid?

Avoid rushed choices, vague medical histories, missing documents, and settlement talks before the key pre-existing condition facts are checked.

The largest mistake is letting the insurer define the old condition without a timeline. A worker should show what life looked like before the injury. Could you lift, walk, drive, reach, or stand? Were you missing work? Were you seeing a doctor often? Those facts matter more than a label in an old chart.

A second mistake is rushing settlement right after the first QME report. The first report may have missing facts. It may not include key job records. It may not explain the split. A short supplemental request can sometimes change the whole case value.

Another mistake is using legal words before the facts are clear. Plain facts win these disputes. What job did you do? What did the doctor restrict? What did the employer know? What changed after the injury? Those answers should come before argument.

Also avoid signing broad papers without review. A release, resignation, voucher clause, or settlement term can close rights you still need. Ask questions before signing. Keep a copy of every page you sign.

How can a lawyer help without making the case harder?

A lawyer can organize the proof, ask the right medical questions, and bring the pre-existing condition issue to the WCAB when the insurer will not fix it.

Good representation should make the claim clearer. It should not turn every issue into a fight. The first job is to sort the facts. The second job is to decide which dispute matters most. Some issues need a letter. Some need a QME question. Some need a hearing.

Yazdchi Law focuses on practical next steps. That may mean getting treatment moving, correcting a report, filing a petition, preparing for deposition, or checking whether settlement terms protect the worker. The plan should fit the injury, the job, and the worker goals.

The consultation is free. The worker should bring claim numbers, adjuster letters, medical reports, job offers, denial letters, and any settlement papers. Clear documents let the review move faster and help identify the first useful step.