The primary insurance amount: the number every benefit is cut from
Your check, your spouse's, your widow's and your children's are all fractions or multiples of one figure.
Checked by Radif Partners · Editorial policy · How we calculate
The primary insurance amount (PIA) is the monthly benefit a worker receives when starting exactly at full retirement age. It comes from the AIME through the bend-point formula of the year the worker turns 62, is rounded down to the next dime, and then grows with every cost-of-living adjustment from that year on, even if benefits have not started. The SSA's case B for 2026 shows the full chain: a worker born in 1959 with maximum earnings has an AIME of $11,463; the 2021 formula (bend points $996 and $6,002) gives $3,317.47, truncated to $3,317.40; five COLAs of 5.9%, 8.7%, 3.2%, 2.5%, 2.8% take it to $4,152.40, paid as $4,152 at 66 and 10 months. Everything else is measured on the PIA: a spouse can get up to 50%, a widow or widower up to 100%, and the family as a whole no more than the family maximum.
Everything your PIA pays for
Worker at full retirement age
$2,609
| Spouse at full retirement age (50%) | $1,304 |
| Widow(er) at full retirement age (100%) | $2,609 |
| Family maximum on this record | $4,764.60 |
Spouse with no PIA of their own; survivor when the worker had not started benefits.
Case B, from AIME to check
The SSA's case B is a worker born in 1959 who earned at or above the taxable maximum every year from 1986 through 2025. That makes 2021 the year of eligibility, so the formula is the 2021 one, whatever the year of retirement.
- 90% of the first $996 of AIME: $896.40.
- 32% of the AIME between $996 and $6,002: $1,601.92.
- 15% of the AIME above $6,002, here $5,461: $819.15.
- Total $3,317.47, truncated to the dime: $3,317.40.
Then come the cost-of-living adjustments. Each one multiplies the PIA of the previous step, and the product is cut to the dime before the next one is applied.
| COLA effective December | Rate | PIA before | Exact product | PIA after (to the dime) |
|---|---|---|---|---|
| 2021 | 5.9% | $3,317.40 | $3,513.127 | $3,513.10 |
| 2022 | 8.7% | $3,513.10 | $3,818.740 | $3,818.70 |
| 2023 | 3.2% | $3,818.70 | $3,940.898 | $3,940.80 |
| 2024 | 2.5% | $3,940.80 | $4,039.320 | $4,039.30 |
| 2025 | 2.8% | $4,039.30 | $4,152.400 | $4,152.40 |
The final PIA is $4,152.40. Case B starts at full retirement age, 66 and 10 months, so no reduction applies and the check is the PIA cut to the dollar: $4,152. Had the same worker waited two more months, to 67, delayed credits would have raised it to $4,207, the amount in the SSA's maximum-benefit table.
Why the dime matters
Truncating instead of rounding costs less than ten cents a month at each step. Over five COLAs the losses compound a little, which is why our engine and the SSA apply the cut at every step rather than once at the end: compute the five rates in one go on $3,317.40 and you get $4,152.60, a little more than the official $4,152.40. The rounding rule is in 20 CFR 404.212.
One PIA, eight amounts
Take the SSA's case A PIA for 2026, $2,609.80, for a worker whose full retirement age is 67. Every benefit on that record is read off it:
| Benefit | Share of the PIA | Monthly amount |
|---|---|---|
| Worker at full retirement age | 100% of PIA | $2,609 |
| Worker at 62 (FRA 67) | 70% | $1,826 |
| Worker at 70 | 124% | $3,236 |
| Spouse at full retirement age | 50% | $1,304 |
| Widow(er) at full retirement age | 100% | $2,609 |
| Child of a retired worker | 50% | $1,304 |
| Child of a deceased worker | 75% | $1,957 |
| Family maximum (2026 formula) | 182.6% | $4,764.60 |
The spouse and child amounts are maximums before the family cap. When a spouse and two children all claim on the same record, their combined benefits are reduced proportionally so the total, with the worker, stays within $4,764.60, the family maximum for a PIA of that size. The family maximum page details the formula. A divorced spouse is paid outside that cap.
What the PIA is not
It is not your check if you start early or late: the reduction at 62 and the credits up to 70 apply to it, not to the AIME. It is not reset by later bend points: someone eligible in 2021 keeps the 2021 formula even when claiming in 2026, as case B shows. And it is not fixed forever: each year's COLA and any recomputation for new earnings raise it.
Same career, different year of 62
Two workers with identical careers relative to the national average wage can have different PIAs in 2026 simply because they turned 62 in different years. The table follows a steady $60,000 career in today's pay, from 22 to 62, for several birth years. The older cohorts have an older formula but more COLAs on top.
| Born | Turned 62 | PIA at 62 | COLAs added | PIA in 2026 |
|---|---|---|---|---|
| 1958 | 2020 | $1,752.30 | 6 | $2,221.70 |
| 1960 | 2022 | $1,871.30 | 4 | $2,211.70 |
| 1962 | 2024 | $2,143.90 | 2 | $2,258.90 |
| 1963 | 2025 | $2,239.00 | 1 | $2,301.60 |
| 1964 | 2026 | $2,345.80 | 0 | $2,345.80 |
The gaps are small because the wage index moves the bend points and the indexed earnings together, while the COLAs follow prices. When prices outpace wages, the COLAs favor those already eligible; when wages outpace prices, the newer formula favors those turning 62 later.
Finding your own PIA
Your Social Security statement shows an estimated benefit at full retirement age, which is a PIA cut to the dollar. To rebuild it, start from your AIME, apply the bend points of the year you turn 62, round down to the dime, then add the COLAs from that year. The calculator does all of it from your earnings record. If you turn 62 after 2026, the figure is an estimate in today's dollars, since your own bend points are not published yet.