Your base period is the 12 months of earnings the Employment Development Department (EDD) uses to decide whether you qualify for benefits and how much you receive each week. It is not the 12 months before you filed. It is the first four of the last five completed calendar quarters before your claim begins, so the most recent three to six months of work usually fall outside it. There is a worked example below, and a calculator that works the dates out for your own claim.
That gap is why the base period matters. Wages you earned right before you stopped working may not count toward this claim, and wages from a job you left over a year ago may still count. This guide covers how the EDD sets the period, the alternate period that applies when the standard one falls short, how wages can be substituted on a disability claim, and what to do if the period on your notice looks wrong.
How the EDD Sets Your Base Period
The EDD works backwards from the date your claim begins, not from the date your job ended. It skips the quarter you file in and the quarter immediately before it, then uses the four quarters before those.
Which date starts the clock depends on the program. For unemployment, your claim begins on the Sunday of the week you file, and that same date opens a 52-week benefit year. For disability, the claim start date is the date your disability began, not the day you got round to filing. That date fixes every quarter below.
Calendar quarters run January to March, April to June, July to September, and October to December. The month your claim begins therefore fixes the whole period.
| If your claim begins in | Your base period is the 12 months ending on |
|---|---|
| January, February, or March | September 30 of the previous year |
| April, May, or June | December 31 of the previous year |
| July, August, or September | March 31 of the same year |
| October, November, or December | June 30 of the same year |
Example of a Regular Base Period
Say you file in April 2026. The EDD skips the quarter you filed in, April to June 2026, and the quarter before it, January to March 2026. Your base period is the four quarters before those: January to December 2025.
Wages you earned in the first three months of 2026 do not count toward this claim. If most of your recent earnings sit in that gap, the alternate base period may apply instead.
Work Out Your Own Base Period
Enter the date your claim begins and this will show both periods, and which quarters fall inside each one.
Pick a date above to see both base periods.
The dates this produces are the EDD’s own rule applied to your claim date. The EDD confirms the figures it actually used on your notice.
When the Alternate Base Period Applies
The alternate base period uses the four most recently completed calendar quarters. In practice it swaps a single quarter: it drops the oldest quarter of the regular period and picks up the quarter immediately before you filed. The quarter you are filing in is never counted either way.
It applies to unemployment claims only, and has done since April 2012. It is used only when the regular base period does not give you enough wages for a valid claim, and you do not have to ask for it: the EDD checks the regular period first and moves to the alternate one automatically.
Example of an Alternate Base Period
Take the same claim filed in April 2026. Where the regular base period was January to December 2025, the alternate base period is April 2025 to March 2026. January to March 2025 drops out, and January to March 2026 comes in.
Where the Alternate Period Makes a Difference
That single swap matters most when your recent work is the part that counts:
- Returning to work. After time out of the workforce, the older quarters can be thin or empty while the recent ones are not.
- A recent job change. Earnings from a newer or better-paid role sit in the later quarter.
- Seasonal or irregular work. A single strong quarter can fall just outside the regular period.
If your earnings are steady across both periods, the alternate one usually changes nothing. Either way, it is worth checking that the wages the EDD used are the ones your employers actually reported.
Special Base Period on a Disability Claim
Disability Insurance claims have no alternate base period. They have a different route, which the EDD calls a special base period. Unlike the alternate period for unemployment, this one you have to ask for.
You can ask for a special base period if your base period was negatively affected by:
- military service
- industrial disability
- a trade dispute
- long-term unemployment
Contact the EDD’s Disability Insurance line on 1-800-480-3287 if any of these describe your claim:
- Not enough base period wages. You may be able to establish a valid claim using a later beginning date, which moves the base period forward with it.
- Not enough wages, and you were job hunting. If you were actively looking for work for 60 days or more in any quarter of the base period, wages paid in other quarters may be substituted.
- Military service, workers’ compensation, or a labor dispute during the base period. Again, wages from other quarters may be substituted.
A Disability Insurance claim needs at least $300 in base period wages to be valid at all, and those wages must have had State Disability Insurance withheld, which shows as CASDI on a pay stub.
Paid Family Leave is a separate program on a separate number, 1-877-238-4373, so check which one your claim falls under before calling. Both are listed on the EDD contact page for disability claims.
What Your Base Period Decides
The base period sets two things: whether you have earned enough to establish a valid claim, and the size of your weekly payment. Both programs work from the wages in that period, but they calculate the payment differently.
- Unemployment Insurance pays a weekly amount between $40 and $450, based on your highest-earning quarter.
- Disability Insurance pays 70 to 90 percent of your wages, depending on income, up to $1,765 a week for claims beginning on or after January 1, 2026.
For a figure based on your own earnings, our EDD benefits calculator gives a general estimate. It is an estimate only: your actual weekly amount is confirmed once the EDD processes your claim. The arithmetic behind both programs is set out in our guide to how unemployment and disability benefits are computed.
What Can Reduce Your Payment
The base period sets the amount. A few things can reduce what actually arrives. Your benefits may be reduced if you:
- have a benefit overpayment from a previous Unemployment Insurance, Paid Family Leave, or Disability Insurance claim
- have late court-ordered child or spousal support payments due
- are working part time, intermittently, or reduced hours
Report all of your income while you are claiming. Unreported earnings are what turn into an overpayment, a penalty, or a false-statement disqualification later on.
If You Think the Wrong Period Was Used
Your Notice of Unemployment Insurance Award or disability determination states the wages the EDD counted. If that figure does not match what you earned, the base period itself is not appealed separately: you appeal the determination that rests on it.
The deadline is 30 calendar days from the mailing date printed on the notice, not the date it reached you. A late appeal is not automatically refused, but you must give a reason, and an Administrative Law Judge at the California Unemployment Insurance Appeals Board (CUIAB) decides whether there was good cause for the delay.
Reasons the counted wages may be wrong include:
- Wrong Social Security number. Wages were reported under a number that is not yours.
- Late or missing employer report. An employer filed after the EDD pulled your record, or did not file at all.
- Wrong claim start date. Also called the benefit year begin date. It shifts the whole period, so an error here moves every quarter.
- Earnings in the wrong quarter. Pay was recorded against a quarter you did not earn it in.
What to expect once an appeal is filed is set out in our guide to the EDD unemployment appeal process. If you have not filed yet, our overview of the unemployment application process shows where the base period fits in.
Keeping your own wage records, pay stubs and W-2s is what makes a discrepancy provable. If the wages on your notice do not match your records, or a determination turns on which quarters were counted, an attorney who works on EDD matters can review how the period was set and advise whether the determination is worth appealing.
