If your spouse died in 2026, this is the last year you can file a joint return, and the joint brackets close on December 31. Starting with 2027, most of the same income is taxed on single brackets about half as wide, and Medicare's surcharge line drops from $218,000 to $109,000.
Planners call this the widow's penalty. It applies to widowers too. Income usually falls after a death, but the brackets shrink faster, so a survivor can pay more tax on less money.
How the penalty works
In the year your spouse dies, you can still file jointly as long as you have not remarried by December 31. You keep the joint standard deduction, the joint brackets, and the joint thresholds for one more return.
The year after, you file single. Unless you have a dependent child at home, which allows a different status for two more years, every line moves at once:
The standard deduction falls from $32,200 to $16,100, plus the age-65 add-on.
The 12% bracket ends at $50,400 of taxable income instead of $100,800.
The 22% bracket ends at $105,700 instead of $211,400.
The $6,000 senior deduction starts phasing out at $75,000 of income instead of $150,000.
The first Medicare surcharge tier starts at $109,000 instead of $218,000.
Income does not fall by half. Social Security pays the survivor the larger of the two benefits, and the smaller one stops. Pensions with a survivor option keep paying. And the IRA usually stays whole, because a surviving spouse can roll the inherited IRA into their own and take the same required distributions the couple was taking.
A worked example with 2026 numbers
Take a married couple in Scottsdale, both 74. His Social Security is $36,000 a year and hers is $24,000. Their IRA required distributions come to $80,000, and they have $10,000 of interest and dividends.
As a couple. $51,000 of their Social Security is taxable, so their income is $141,000. That is under $150,000, so they keep the full senior deduction for both of them. After the standard deduction, the age-65 add-ons and the senior deduction, taxable income is $93,500. Federal tax is about $10,724.
As a survivor. He dies. She keeps his $36,000 benefit and hers stops. She rolls his IRA into hers, so the distributions stay at $80,000. Her income is now $120,600, down $20,400.
On a single return, $30,600 of her Social Security is taxable, her senior deduction shrinks to about $3,264, and her taxable income comes to $99,186. Her federal tax is about $16,533.
Her income fell 14%. Her federal tax rose by about $5,800, or 54%. Her next dollar of income is taxed at about 23% instead of 12%.
The Medicare bill
Medicare's income-related surcharge, known as IRMAA, uses the tax return from two years earlier. Her first single return, for 2027, sets her Medicare premium for 2029.
At $120,600 she is about $11,600 over today's $109,000 single threshold. In the first surcharge tier, Part B costs $284.10 a month instead of the standard $202.90, and with the Part D surcharge that adds roughly $1,148 a year. The 2029 thresholds will rise with inflation and have not been published, so treat this as an estimate. The line would need to rise by about 11% to clear her.
As a couple, their $141,000 sat $77,000 under the joint line.
Add the federal tax and the Medicare surcharge, and the same household pays about $6,950 more a year after the first death, on $20,400 less income.
Form SSA-44 is the first thing to file
The two-year lookback can also work against a survivor in the other direction. Your Medicare premium for 2026 and 2027 is set from your 2024 and 2025 returns, when there were two of you with two incomes. If that joint income put you in a surcharge tier, you keep paying it on income you no longer have.
Form SSA-44 asks Social Security to use a more recent, lower income because of a life-changing event, and the death of a spouse qualifies. You file it with Social Security along with proof of the death and an estimate of your current income. If your premium notice shows a surcharge, file it as soon as the estimate is reasonable.
The Arizona wrinkle: a full step-up on community property
When someone dies, the cost basis of what they owned generally resets to its value on the date of death. Gains built up during their life are never taxed.
In most states, a couple's jointly owned brokerage account gets that reset on the deceased spouse's half only. Arizona is a community property state, and federal tax law resets the basis on both halves of community property at the first death.
Say the couple above owned a brokerage account they bought for $400,000 that was worth $1,000,000 when he died. In a common-law state, her new basis would be $700,000: his half reset to $500,000, her half still at $200,000. If she sold, she would owe tax on $300,000 of gain.
If the account was community property, her basis is $1,000,000 and the gain is zero. At the 15% long-term rate, that is about $45,000 of federal tax she does not owe, plus $7,500 of Arizona tax at 2.5%. The 3.8% surtax on investment income could have added more.
Two cautions. First, not everything a married couple in Arizona owns is community property. Assets acquired during the marriage while living here generally are, but a prenuptial or postnuptial agreement, an inheritance kept separate, or money brought from a common-law state can change that. Confirming how your accounts are characterized is work to do alongside your estate attorney. Second, custodians do not always know an account was community property. Check that the basis was updated on both halves, not only the decedent's.
What to do before December 31
If your spouse died in 2026:
Use the last joint return. In the example, the 2026 joint return still has about $7,300 of room in the 12% bracket. A Roth conversion that fills it costs 12%. The same dollars withdrawn on her single return later cost about 23%. Above that, a conversion this year costs about the same rate she will pay later, so size it against her own future returns before filling the 22% bracket.
Finish your spouse's 2026 RMD. If your spouse owed a required distribution this year and had not taken all of it, the remainder generally still has to come out by December 31.
Confirm the step-up. If the account was community property, both halves should show date-of-death basis. A full step-up also makes it a cheap year to rebalance or diversify a concentrated position.
File SSA-44 if your current premium carries a surcharge based on joint income.
If you are both living: the widow's penalty is a reason to do Roth conversions while you are both alive. Unless you die together, one of you will file single. Each year they are both alive, the couple in the example has $7,300 of room left in the 12% bracket. Dollars converted there pay 12%. Dollars left in the IRA for the survivor come out at about 23%.
What it costs to get this wrong
For the couple above, doing nothing costs about $6,950 a year from the first death on: $5,800 in federal tax and $1,150 in Medicare surcharges. Over ten years of survivorship that is roughly $70,000, before inflation and before RMDs grow.
Missing the community property step-up can cost more in a single trade: $52,500 of tax on a sale that should have cost nothing.
I am an Enrolled Agent, admitted to practice before the Internal Revenue Service, and I prepare returns alongside the planning work, so the last joint return and the first single one get handled by the same person.
If you want the joint and single years modeled against your own return before December, that is a conversation worth having.
Aaron Randak, CFP®, EA · Golden Acre Wealth Management · Scottsdale, Arizona
Golden Acre LLC dba Golden Acre Wealth Management is an investment adviser registered with the Arizona Corporation Commission, CRD #337930. This article is educational and is not individualized tax, investment, or legal advice. Tax rules change and their application depends on your specific circumstances. Medicare premium thresholds for 2029 have not been published; figures shown use 2026 amounts for illustration. Community property characterization depends on your facts and is a question for your estate attorney.