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Survivor benefits are off unless you turn them on. With the survivor option on, after the first partner’s modeled death CoastMath pays the survivor the larger of their own benefit and the deceased partner’s benefit, never both. It does this by adding a top-up equal to the difference, starting in the month the survivor reaches full retirement age for survivor benefits.
When both partners’ streams use PIA basis, the same option calculates the survivor benefit from both primary insurance amounts instead, which also covers early claims and deaths before claiming; see Survivor benefits from both PIAs. With the option off, the deceased partner’s benefit simply stops and the survivor keeps only their own. Spousal benefits while both partners are alive are calculated only for PIA-basis couples; see Social Security benefits.
The option works only on the household horizon, where the projection continues after the first death; see When a partner dies. It also needs facts CoastMath can’t infer, so the setting asks you to confirm them.
- Under Partner and estate, set Plan ends to At the last survivor’s longevity age.
- Enter Partner birth year, Partner birth month and Partner life expectancy (age). Your own birth month must also be on file.
- Set Survivor Social Security policy to Claimed benefit top-up at survivor full retirement age.
- Check Survivor eligibility is confirmed, including remarriage rules and write the basis for that in Survivor eligibility note, for example the date of the benefit statement you relied on.
- Save. The next projection applies the top-up.
Each partner’s benefit must be its own Social Security stream with the right Income recipient. With Benefit amount basis, the partner who dies first needs exactly one active stream that:
- starts at or after that partner’s full retirement age, from a claiming age or a milestone set by an age or a date;
- starts no later than the year of their modeled death, so it is already being paid;
- has no end milestone.
The survivor may have one stream of their own or none. If the plan doesn’t meet these conditions, the projection doesn’t run rather than guess; see Projection errors.
The deceased partner’s stream stops paying the January after their death year. From the later of that January and the survivor’s full-retirement-age month, CoastMath adds a line called Social Security survivor top-up through the end of the survivor’s own life-expectancy year.
Survivor top-up for the year=Deceased partner’s benefit×eligible share of the year−survivor’s own benefit×share of the year both are paid
Both amounts are the full-year rates for the year. The deceased partner’s benefit keeps the claiming amount and cost-of-living growth it had while they were alive.
The top-up is never negative. If the survivor’s own benefit is larger, nothing is added. Months when the survivor is eligible but hasn’t yet claimed their own benefit receive the full deceased benefit. The top-up is taxed like any other Social Security benefit.
Full retirement age for survivor benefits uses its own schedule, two birth years behind the retirement schedule: 66 for survivors born 1945–1956, rising two months per birth year to 67 for those born in 1962 or later.
When both partners have one active Social Security stream with Benefit basis set to PIA and the survivor option is on, CoastMath works out the survivor benefit from the deceased partner’s primary insurance amount (PIA). Mixing a PIA-basis stream with a Benefit amount stream stops the projection.
- Deceased claimed at or after full retirement age: the survivor amount is the deceased’s benefit, including any delayed credits.
- Deceased claimed early: the survivor amount is the PIA, limited to the larger of the deceased’s reduced benefit and 82.5% of the PIA.
- Deceased died before claiming: the PIA, plus delayed credits earned through the month before death if they were past full retirement age.
The survivor benefit starts at the later of the January after the death year and the survivor’s own claim month. If that is before the survivor’s full retirement age for survivor benefits, it is reduced in equal monthly steps to 71.5% at 60; the early-claim limit above applies after this reduction. The survivor’s expected benefit percentage applies. The survivor receives the larger of their own benefit and the survivor benefit, as the same Social Security survivor top-up line, and any spousal benefit stops at the death.
| Deceased’s reduced benefit: 75% of $2,00048 months before full retirement age of 66 | $1,500 | |
|---|---|---|
| Limit: larger of $1,500 and 82.5% of $2,000 | $1,650 | |
| − | Survivor’s own benefit: $800 × 108%Delayed credits for claiming at 67 | $864 |
| = | Monthly top-up from January 2027 | $786 |
| × | Months | 12 |
| = | Survivor top-up in 2027With 0% inflation | $9,432 |
In 2026 the survivor also received a $2,400 spousal benefit (half of $2,000 less $800, at full retirement age); it stops in 2027.
Alex, born January 1956, claimed $42,000 a year at 70 in 2026. Sam, born September 1968, claims $18,000 a year at 62, from September 2030. Alex’s life expectancy is 77, so the modeled death is the end of 2033. Sam’s full retirement age for survivor benefits is 67, reached in September 2035. Inflation is set to 0% to keep the arithmetic visible.
- Household total
- Sam’s own benefit
In 2034 Sam receives only their own benefit: the top-up waits for Sam’s survivor full retirement age.
Show data
| Year | Household total | Sam’s own benefit | Survivor top-up |
|---|---|---|---|
| 2029 | $42,000 | $0 | $0 |
| 2030 | $48,000 | $6,000 | $0 |
| 2031 | $60,000 | $18,000 | $0 |
| 2032 | $60,000 | $18,000 | $0 |
| 2033 | $60,000 | $18,000 | $0 |
| 2034 | $18,000 | $18,000 | $0 |
| 2035 | $26,000 | $18,000 | $8,000 |
| 2036 | $42,000 | $18,000 | $24,000 |
| 2037 | $42,000 | $18,000 | $24,000 |
| Alex’s benefit, September–December$42,000 × 4 ÷ 12 | $14,000 | |
|---|---|---|
| − | Sam’s own benefit, same months$18,000 × 4 ÷ 12 | $6,000 |
| = | Survivor top-up | $8,000 |
| + | Sam’s own benefit, full year | $18,000 |
| = | Social Security for 2035 | $26,000 |
From 2036 the top-up is $24,000 a year and the total is $42,000, Alex’s benefit.
With the survivor option off, the same plan pays Sam $18,000 a year from 2034 on.
A PIA-basis benefit can carry one former spouse’s record. CoastMath then adds a divorced-spouse benefit while your former spouse is alive and a surviving divorced spouse benefit after their death. Your former spouse isn’t part of the household: only their PIA, birth date, claiming age and death year are used.
| Requirement | Divorced spouse | Surviving divorced spouse |
|---|---|---|
| Marriage length | 10 years or more | 10 years or more |
| Your age | 62 or older, and you have claimed your own benefit | 60 or older, from the January after their death year |
| Your former spouse | Alive and 62 or older, and either claimed or divorced from you for 2 years | Deceased |
| Your current marriage | You must be unmarried | A marriage that began at 60 or later doesn’t matter; an earlier one bars the benefit while it lasts |
| Amount | Half their PIA minus your PIA, reduced if you start before full retirement age | Their PIA with delayed credits, or the reduced-benefit limit if they claimed early, reduced for your age, minus your own benefit |
| Half your former spouse’s PIA | $1,500 | |
|---|---|---|
| − | Your PIA | $1,000 |
| = | Monthly excess | $500 |
| × | Claiming at full retirement age | 1.00 |
| = | Divorced-spouse benefit a yearClaiming at 62 instead: 65% of the excess, $3,900 | $6,000 |
Before cost-of-living adjustments. Your own benefit, $12,000 a year at full retirement age, is paid as well.
You’re treated as married in the years your filing status is married and your partner in the plan is alive. A filing status change to single, or your partner’s modeled death, makes you eligible again. If you married your current spouse before the plan starts, enter the year it began so the survivor rule can tell whether you remarried at 60 or later; when it’s blank, CoastMath assumes it was earlier.
Only one auxiliary benefit is paid each month. When a spousal benefit from your current partner or a survivor top-up overlaps a divorced-spouse or surviving divorced spouse amount, CoastMath pays the larger, not both. When your partner’s earnings withhold their spousal benefit to you, the comparison uses what is still payable, so a divorced-spouse or surviving divorced spouse amount can be paid in full instead. Divorced-spouse amounts are counted with your own benefit in the earnings test before full retirement age. At full retirement age, a spousal or divorced-spouse benefit that started early is refigured without the months it was fully withheld, so less of the early reduction applies from then on.
When the option is on but the plan doesn’t fit it, the projection fails with a general error. Check these in order:
For how the claimed amounts and their growth are set, see Social Security benefits.