Benefit formula
Social Security Primary Insurance Amount (PIA)
Primary Insurance Amount (PIA) is the basic benefit associated with claiming at full retirement age, before the early-retirement reduction or delayed-retirement credits. It is calculated from AIME using the bend points for the worker's eligibility year.
SSA sources reviewed September 9, 2026
- At full retirement age
- PIA before final rounding
- Claim before FRA
- Reduced from PIA
- Claim after FRA
- Credits added through 70
The 2026 formula
For a worker first eligible in 2026, SSA applies 90% to the first $1,286 of AIME, 32% to AIME from $1,286 through $7,749, and 15% to AIME above $7,749. SSA then applies its prescribed rounding rules.
For example, SSA's published 2026 case with an AIME of $5,825 produces a PIA of $2,609.80 after truncation. The formula year is tied to first eligibility, not simply the calendar year when a person chooses to file.
PIA is not always the check amount
The monthly retirement amount can be lower than PIA when benefits begin before FRA or higher after delayed credits. COLAs can also affect payable benefits. This is why a statement showing PIA and a claiming-age estimate may display different numbers without being contradictory.
Use PIA as the common baseline
When comparing filing dates, hold the earnings record constant and examine each monthly amount relative to the same PIA. Claiming Planner shows PIA and the adjustment percentage in its detailed results.
Official sources
Use these SSA pages to verify the rules and current annual amounts:
Educational information only. This page covers retired-worker benefits and is not personalized financial, tax, or legal advice. Confirm filing decisions and official benefit amounts with the Social Security Administration.