7 Filing Status Errors Widows Make the First Year Alone

filing errors widows make in the first year — Image Source: Shutterstock

Losing a partner is one of life’s most devastating transitions, and the last thing anyone wants to think about while grieving is the IRS. But as we head into the 2026 tax season, the rules for surviving spouses have shifted under the One Big Beautiful Bill Act (OBBBA). There is a phenomenon financial pros call the “Widow’s Penalty,” where a surviving spouse’s tax bill can nearly double because they move into a less favorable tax bracket while losing a portion of their household income.

The good news is that the tax code provides a “grace period” to help you adjust. The bad news? Many widows miss out on these benefits because they choose the wrong filing status during that critical first year. If you are navigating your first tax season alone, here are the seven most common errors to avoid so you can keep your financial footing.

1. Filing as “Single” Too Early

The most common mistake widows make in 2026 is filing as “Single” for the year their spouse passed away. Under IRS rules, if your spouse died at any point during 2025, you are still considered “Married” for the entire tax year.

According to AARP, you should almost always file as Married Filing Jointly for the year of death. This allows you to use the higher 2026 standard deduction of $32,200 (plus any senior bonuses) and the more generous joint tax brackets. Filing as single prematurely can cost you thousands in unnecessary taxes by cutting your deduction in half and pushing your income into a higher bracket.

2. Missing the “Qualifying Surviving Spouse” Window

If you have a dependent child living at home, you don’t have to jump to “Single” or “Head of Household” status once the first year ends. For the two years following the year of your spouse’s death, you may be eligible for the Qualifying Surviving Spouse (QSS) status.

As reported by H&R Block, this status allows you to keep the “Married Filing Jointly” tax rates and the highest standard deduction even though you are filing alone. If your spouse passed in 2025, you can use QSS for your 2026 and 2027 returns. Many widows overlook this, defaulting to “Head of Household” and losing out on the more robust protection of the QSS status.

3. Forgetting the OBBBA “Senior Bonus” for a Deceased Spouse

In 2026, the OBBBA allows an extra $6,000 deduction for seniors age 65 and older. A common error on a final joint return is only claiming this bonus for the surviving spouse. If your spouse was also 65 or older at the time of their death in 2025, you are entitled to a $12,000 total bonus on your joint return.

According to IRS Section 70103, this deduction applies even if the spouse was only alive for a single day of the tax year. Don’t leave that second $6,000 on the table; it’s a specific “legacy” benefit designed to help with the final expenses of a household.

4. Failing to Elect “Portability” (Form 706)

Even if you don’t owe estate taxes, you might be making a million-dollar mistake by not filing a “Portability” return. Portability allows a surviving spouse to “inherit” their deceased partner’s unused estate tax exemption—which in 2026 has jumped to a staggering $15 million.

As noted in a recent Tax Court decision, this election is not automatic. You must file a Form 706 even if no tax is due. If you don’t “port” that exemption now, and your own assets grow significantly before you pass away, your heirs could be hit with a massive tax bill that could have been entirely avoided with a simple 2026 filing.

5. Miscalculating the “Step-Up” in Basis

When a spouse passes away, the “basis” (the original purchase price) of your shared assets is often “stepped up” to the current market value. This is a massive tax gift because it allows you to sell a home or stocks with little to no capital gains tax.

A common error for widows is selling an asset and paying tax on the original price because they didn’t know about the step-up. In 2026, the OBBBA kept this “Step-Up in Basis” intact. Before you sell anything to simplify your life, talk to an accountant about the date-of-death valuation to ensure you aren’t paying a “phantom” tax on your inheritance.

6. Filing “Separate” Returns Out of Habit

If you and your spouse always filed separately for legal or financial reasons, you might be tempted to continue that in the year of death. However, in 2026, the OBBBA has made the Married Filing Separately status ineligible for the new $6,000 senior deduction and the $40,000 SALT cap.

Switching to a joint return for the final year is almost always the smarter move. It allows you to “capture” the final year of joint tax brackets and use them to offset any large distributions you might need to take from an inherited IRA. Habit can be your enemy during the first year alone—always run the numbers for a joint filing.

7. The “Remarriage” Trap

It may seem far off, but if you remarry during the same year your spouse passed away, you lose the right to file jointly with your deceased spouse. You would instead file jointly with your new spouse.

According to eFile.com, this can create a complex situation where your deceased spouse’s final income must be reported on a “Married Filing Separately” return, which is the least favorable status in 2026. If a new marriage is in your future, consult a tax pro to understand how the timing will impact the final tax legacy of your late partner.

Taking the First Step Alone

The 2026 tax season is a heavy lift for anyone, but for a new widow, it can feel insurmountable. The key to surviving the “Widow’s Penalty” is to maximize the grace periods the IRS provides. Use the Married Filing Jointly status for 2025, look into Qualifying Surviving Spouse for 2026, and don’t forget to claim the OBBBA senior bonuses for both of you. By avoiding these seven common errors, you can protect your financial future while honoring the legacy of the life you built together.

Are you navigating your first tax season as a surviving spouse, or helping a loved one do so? Leave a comment below and share which filing status has been the most confusing for you to navigate this year!