How Are Permanent Disability Ratings Calculated in California?

In California, a permanent disability rating is calculated by taking your doctor’s whole person impairment (WPI) under the AMA Guides, multiplying it by 1.4 for injuries on or after January 1, 2013, adjusting it for your occupation and your age at the time of injury, and then reducing it for any apportionment to causes other than work. The result is a percentage between 0% and 100%, and that percentage decides how many weeks of permanent disability (PD) benefits you receive.

Small changes in that percentage matter. Every step, from the WPI the doctor picks to the way two body parts are combined, can move your final rating by several points, and each point adds weeks of payments. Many injured workers never see how their number was built, so they cannot tell when a step was done wrong.

This guide explains how ratings work: the formula, the occupation and age adjustments, how multiple impairments are combined, apportionment, who does the rating, and how to dispute it. If you already have a rating and want to know the dollar amount, see our companion guide, What your rating pays: the 2026 permanent disability chart.

What a permanent disability rating is

Permanent disability is the part of your work injury that does not go away. Once your condition stops improving with treatment, your doctor declares you at maximum medical improvement (MMI), also called permanent and stationary. At that point the doctor measures what you have lost.

California law says the rating must account for three things: the nature of the physical injury or disfigurement, your occupation, and your age at the time of injury (Labor Code section 4660.1(a)). The “nature of the injury” part comes from the AMA Guides to the Evaluation of Permanent Impairment, 5th Edition, which the statute adopts by name (section 4660.1(b)).

A rating is not a measure of whether you can still work. Many workers with a rating go back to their old job or a modified one. A rating of 100% is different: it means permanent total disability, which is paid for life (Labor Code section 4659(b)). Some injuries are presumed total by law, including loss of both eyes or both hands, practically total paralysis, and a brain injury that causes permanent mental incapacity (section 4662). See our permanent total disability guide for those cases.

How are permanent disability ratings calculated in California?

For injuries on or after January 1, 2013, the rating is built in the same order every time. The rating tables come from the state’s Permanent Disability Rating Schedule (PDRS).

Step	What happens	Source
1. Impairment	The doctor assigns a whole person impairment (WPI) percentage for each injured body part or system	AMA Guides, 5th Ed.; Lab. Code 4660.1(b)
2. 1.4 adjustment	Each WPI is multiplied by 1.4	Lab. Code 4660.1(b)
3. Occupation	The rating is adjusted up or down for how that impairment affects your type of job	Lab. Code 4660.1(a), (d); PDRS
4. Age	The rating is adjusted for your age on the date of injury	Lab. Code 4660.1(a), (d); PDRS
5. Combining	Ratings for separate body parts are combined, usually with the Combined Values Chart	PDRS; Vigil (WCAB en banc 2024)
6. Apportionment	Any share caused by something other than this work injury is subtracted	Lab. Code 4663, 4664

The first number, the WPI, does the most work. A doctor measures range of motion, strength, nerve findings, imaging and other criteria, then applies the AMA Guides chapter for that body part. You can learn how WPI is assigned in our whole person impairment guide.

Older injuries follow a different formula. For injuries before January 1, 2013, the 2005 PDRS applies a “future earning capacity” (FEC) adjustment instead of the flat 1.4 multiplier (Labor Code section 4660). If you see an FEC step in a rating for a 2013-or-later injury, something is wrong.

💡 Example: Maria, a hypothetical warehouse worker injured in 2025, is found to have 10% WPI for her shoulder. Step 2 makes it 10 × 1.4 = 14%. The occupation and age steps then move that number up or down based on her job group and age. If her final rating comes out at 15%, she is owed 50.5 weeks of PD under Labor Code section 4658(e).

Watch: injured at work in California

Our attorneys explain what your employer must do after a work injury, and what to do in the first 24 hours to protect your claim.

Occupation and age adjustments

The same injury does not affect every worker the same way. A knee impairment limits a roofer more than a receptionist. The PDRS handles this by assigning your job to an occupational group and then adjusting each impairment based on how much that body part matters in that group. Physically demanding jobs generally produce a higher adjustment for back, arm and leg injuries.

Age works the same way. The schedule adjusts the rating for your age on the date of injury, and older workers generally receive a higher adjustment than younger workers with the same impairment.

Two common mistakes happen at this step:

• Wrong occupation. The rater picks a job title that does not match what you actually did. A “supervisor” who still lifts and climbs all day should not be rated as an office worker.
• Wrong date of injury. For a cumulative trauma claim, the date of injury can change both the age adjustment and which formula applies.

Always compare the job description in the rating with your real duties, and keep records of what you did on a typical day.

Combining more than one impairment

If more than one body part is injured, the separate ratings are combined into one number. The default method is the Combined Values Chart (CVC) in the PDRS. The CVC is not simple addition. It uses the formula A + B × (1 − A), which treats the second impairment as affecting only the “remaining” part of you.

For example, a 20% rating and a 10% rating combine to 20 + 10 × 0.80 = 28%, not 30%. The gap grows as more body parts are added.

The CVC is not the last word. In Vigil v. County of Kern (2024), an en banc decision of the Workers’ Compensation Appeals Board, the Board held that the CVC can be rebutted and the ratings added together. To do that, you must show how each impairment affects your activities of daily living (ADLs), and either:

• there is no overlap between the ADL effects of the body parts being rated, or
• there is overlap, but the overlap increases or amplifies the impact on those activities.

The Board also said that a doctor simply using the word “synergy” is not enough. The medical report has to analyze your daily activities in detail. That is why the way your doctor writes the report matters as much as the numbers in it.

Psychiatric and some other add-on ratings have their own limits. For injuries on or after January 1, 2013, a physical injury generally cannot increase the rating for sleep dysfunction, sexual dysfunction or a psychiatric disorder that results from it (Labor Code section 4660.1(c)). The only exception is for a psychiatric disorder, whose rating can still be increased if the injury was catastrophic or you were the victim of, or directly exposed to, a significant violent act. You can still get treatment for those conditions.

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Apportionment: when part of your disability is not from work

Apportionment can lower a rating more than any other step. Under Labor Code section 4663, apportionment of permanent disability is based on causation. Every doctor’s report on permanent disability must address it, giving an approximate percentage caused by the work injury and an approximate percentage caused by other factors, such as earlier injuries or degenerative changes.

The employer is liable only for the percentage of permanent disability directly caused by the work injury (Labor Code section 4664(a)). If you received a prior permanent disability award, the law conclusively presumes that the earlier disability still exists when you are hurt again (section 4664(b)), which can reduce what this employer owes.

Apportionment is often where cases are won or lost. A doctor’s opinion on apportionment must be explained, not just stated. If a report blames 40% of your back on “degeneration” without explaining how and why, it can be challenged. Our article on Labor Code section 4663 apportionment covers this in more detail.

Who decides your rating

Several people play a part, and knowing who does what helps you spot problems.

• Your primary treating physician (PTP). When you reach MMI, your treating doctor usually writes a permanent and stationary report with WPI, work restrictions and apportionment.
• A Qualified Medical Evaluator (QME) or Agreed Medical Evaluator (AME). If either side disputes the treating doctor’s findings, the dispute goes to a QME from a state panel or, in represented cases, to an AME both sides agree on. See QME vs. AME.
• The Disability Evaluation Unit (DEU). The DWC’s raters turn medical findings into a rating. If you do not have a lawyer, the administrative director must calculate your rating within 20 days of receiving the QME’s report and serve it on you and the employer (Labor Code section 4061(e)).
• A workers’ compensation judge. If the parties cannot agree, a judge at the Workers’ Compensation Appeals Board decides the rating based on the medical evidence.

A dispute over the existence or extent of permanent impairment generally cannot be set for a hearing until you have been evaluated by a treating physician and by a QME or AME (Labor Code section 4061(i)).

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How to dispute a permanent disability rating

A low rating is not final just because a doctor or the insurer says so. These are the usual steps:

1. Get every report. Ask for the full treating, QME or AME report and any DEU rating. Read the WPI tables, the job description and the apportionment section.
2. Check the formula. Confirm the date of injury, that the 1.4 multiplier was used for a 2013-or-later injury, that your occupation is right, and that the age is correct.
3. Look at how body parts were combined. If your injuries affect different daily activities, or make each other worse, ask whether the CVC can be rebutted under Vigil.
4. Challenge weak apportionment. An apportionment opinion without a clear explanation may not be substantial medical evidence.
5. Ask for a supplemental report or deposition. The evaluator can be sent new records or questions, or be cross-examined under oath.
6. Use the QME or AME process. If you disagree with your treating doctor, the dispute goes to a QME or AME. If you disagree with a QME, the next step is usually a supplemental report, a deposition or a hearing, not simply a second panel. See how to dispute a biased QME or AME report.
7. Ask a judge to decide. If the issue is not resolved, a workers’ compensation judge can rule on the rating.

Talk to a workers’ comp attorney before you accept a rating or sign a settlement based on it. Once a case settles, it is usually very hard to reopen the rating.

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From rating to dollars

Your final rating is turned into money with a separate formula: the rating sets the number of weeks under Labor Code section 4658(e), and the weekly rate is two-thirds of your average weekly earnings, between $160 and $290 a week for injuries on or after January 1, 2014. For example, a 25% rating equals 100.75 weeks, which is $16,120 at the minimum rate and $29,217.50 at the maximum.

Ratings of 70% or more add a life pension, and 100% is paid for life. For the full week-by-week chart, payment timing, lump sums and the job displacement voucher, read What your rating pays: the 2026 permanent disability chart, or run your own numbers in our workers’ comp calculator.

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Frequently asked questions

How are permanent disability ratings calculated in California?

For injuries on or after January 1, 2013, the doctor’s WPI under the AMA Guides, 5th Edition, is multiplied by 1.4, then adjusted for your occupation and age, combined with ratings for other body parts, and reduced for any apportionment (Labor Code sections 4660.1, 4663 and 4664).

Does the 1.4 multiplier apply to my injury?

It applies to injuries on or after January 1, 2013. Older injuries are rated under the 2005 schedule with a future earning capacity adjustment instead.

Can my final rating be higher than my WPI?

Often, yes. The 1.4 multiplier and the occupation and age adjustments usually raise the number. Apportionment can lower it, and the Combined Values Chart keeps combined ratings below simple addition unless it is rebutted.

Can I get a permanent disability rating if I go back to work?

Yes. The rating measures your permanent impairment, not whether you are working. Returning to work can affect when some payments are made and whether you receive a job displacement voucher, but not the rating itself.

What if I had an earlier injury to the same body part?

If you received a prior permanent disability award, the law presumes that disability still exists (Labor Code section 4664(b)), and the new rating may be reduced by it. Without a prior award, the doctor must explain any apportionment to earlier conditions.

How long does it take to get a rating?

The rating can be done only after you reach MMI. For unrepresented workers, the state must calculate the rating within 20 days of receiving the QME report. In represented cases, timing depends on the medical-legal process and any disputes.

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