What Is California Labor Code §4657: Partial Disability Pay Calculation?

In case of temporary partial disability the weekly loss in wages shall consist of the difference between the average weekly earnings of the injured employee and the weekly amount which the injured employee will probably be able to earn during the disability, to be determined in view of the nature and extent of the injury. In computing such probable earnings, due regard shall be given to the ability of the injured employee to compete in an open labor market. If evidence of exact loss of earnings is lacking, such weekly loss in wages may be computed from the proportionate loss of physical ability or earning power caused by the injury.

What Is Labor Code 4657?

Labor Code 4657 is the measuring rule: it tells a claims administrator how to work out the wage loss that your partial disability pay is built on.

A work injury does not always take you off the job completely. A doctor's restrictions may let you return to lighter duty, fewer hours, or a lower-paying task. When that happens, you are no longer fully disabled, but you earn less than before. Labor Code 4657 is the section that tells a claims administrator how to put a number on that gap. It does not set the percentage you are paid. It sets the wage-loss figure that percentage is later applied to.

This section applies to you if you have an accepted California work injury, a doctor has released you to modified or reduced work, and your pay, hours, or duties have dropped because of the injury. It does not apply while you are completely unable to work. That stage runs through Labor Code 4653 instead.

How Is the Weekly Wage Loss Actually Calculated?

The law uses one of two methods, depending on whether your exact earnings loss can be shown.

The standard method is a subtraction. Start with your average weekly earnings before the injury. Subtract the weekly amount you can probably still earn during the disability, based on the nature and extent of the injury. The statute also says this estimate must weigh your real ability to compete for work in the open labor market, not an idealized wage you might earn under perfect conditions.

The second method is a fallback. When exact proof of your lost earnings is not available, the weekly loss can instead be worked out from the proportionate loss of physical ability or earning power the injury caused. The table below lines up the two paths.

How Does That Figure Turn Into Your Weekly Check?

This rule only measures the wage loss. A different section sets what share of that loss gets paid.

Labor Code 4654 pays two-thirds of the weekly wage loss that this section measures, as your temporary partial disability payment. The two sections work as a pair. One answers how big the gap is. The other answers how much of that gap you are paid. A dispute about your check can turn on either number: the wage-loss figure, or the two-thirds math applied to it.

Does Anything Reduce the Weekly Partial Disability Payment?

Yes. Labor Code 4654 reduces the payment by unemployment or extended duration benefits you received for that same period.

Labor Code 4654 says the two-thirds payment is cut by the amount of unemployment compensation benefits and extended duration benefits you actually received during the period of partial disability. In plain terms, if you drew unemployment-type benefits for a week that this section already counted as a wage-loss week, that amount comes off the partial disability check for the same week, so the two benefits do not simply stack.

How Does This Fit With Other Temporary Disability Rules?

Several other sections set pieces of the math that this rule does not cover on its own.

Your average weekly earnings figure is not just your hourly rate times your hours. Labor Code 4454 says that figure includes overtime and the market value of job perks such as board or lodging. It leaves out reimbursed work expenses and most employee benefit programs. Labor Code 4453 then puts a statutory floor and ceiling on that number. The figure that feeds this calculation cannot fall below, or rise above, those limits.

Total weeks matter too. For most claims, Labor Code 4656 caps temporary disability, including partial disability weeks, at 104 compensable weeks within five years of the injury. A short list of serious conditions gets a longer period. A claim can move between full disability under Labor Code 4653 and partial disability under this section more than once. Both kinds of weeks typically draw on that same overall cap. For the bigger difference between the two stages, see TTD vs. TPD in a California workers' comp claim.

What Should You Save or Ask About a Labor Code 4657 Calculation?

Keep your own pay records next to your claim payment notices, and ask for the calculation in writing if the numbers do not line up.

Save your pay stubs, W-2 forms, and schedule records from before the injury, plus every pay stub or earnings record from your modified-duty work after it. Keep the doctor's written restrictions and any letter offering you modified work. Note the date each time your hours, pay, or duties change, because those dates decide which week's wage-loss figure applies.

If a weekly check looks low, ask the claims administrator three things: the average weekly earnings number it used, the method it applied to estimate your probable earnings or your proportionate loss, and the records behind that number. A written answer gives you something to compare against your own pay stubs, and against the Labor Code 4656 week count if your claim has been open a long time.

If your partial disability check does not match your actual drop in pay, hours, or duties, gather your pay records and claim notices before you raise the issue. Yazdchi Law P.C. reviews each matter individually and decides separately whether to take it on. Call (661) 273-1780 or use the contact form for a free initial consultation, and ask about the full California workers' comp claim process if you are earlier in your case.