Issues

No Tax on Social Security? The IRS Says Otherwise

You heard Social Security isn't taxed anymore—then the IRS sent a bill on your benefits. Here's why § 86 still applies and how to fight the number.

You heard the news: "No tax on Social Security." So when a notice from the IRS landed saying you owe tax on your benefits, it didn't just feel wrong—it felt impossible. You may have left your Social Security off your return entirely because you were sure it was tax-free. Now there's a CP2000 or a Notice of Deficiency proposing extra tax, a penalty, and interest on top.

Here's the truth, plainly: the 2025 law did not make Social Security tax-free. It created a brand-new, separate tax break for seniors—and that break is real and worth a lot to many retirees—but it left the actual rule that taxes benefits completely untouched. That rule is IRC § 86, it has been on the books since 1983, and it still works exactly the way it always has. The "no tax on Social Security" headline is the single biggest reason these disputes are landing in mailboxes right now.

The good news is that these are among the most winnable notices the IRS sends, because § 86 is pure arithmetic. The fight is almost never about the law—it's about the numbers that went into the formula. Get those right and the bill often shrinks dramatically, sometimes to zero. This is the substantive guide to that fight: what the new law actually did, how § 86 really works, the trap that catches married couples filing separately, and exactly how to recompute the IRS's number and push back.

Which notice are you holding? A CP2000 is an automated proposed change—the IRS's computer matched a benefit form you didn't fully account for and is proposing extra tax. No Tax Court clock has started, and you can still head it off; that procedure is owned by How To Respond to a CP2000 Notice. A Notice of Deficiency—the "90-day letter"—is the IRS's formal determination, and it starts the clock: you have 90 days to petition Tax Court (150 days if it was addressed outside the US), and that deadline cannot be extended. Figure out which one is in your hands first, because it sets both your deadline and your options.

First, What the 2025 Law Actually Did

The One Big Beautiful Bill Act (Public Law 119-21), signed July 4, 2025, did not repeal the tax on Social Security and did not change § 86 at all. What it created, in § 70103, is a separate, temporary senior deduction—new IRC § 151(d)(5)(C). Here is what it really is:

$6,000 per qualifying individual who is 65 or older. On a joint return where both spouses are 65 or older, that's $12,000 total.
Temporary: it applies to tax years 2025 through 2028, then it sunsets.
It phases out as income rises—the $6,000 is reduced by 6% of the amount your modified adjusted gross income exceeds $75,000 (single) or $150,000 (joint), and disappears entirely at $175,000 single / $250,000 joint.
Married filing separately cannot claim it at all—you must file a joint return.
It's on top of the standard deduction. You get it whether you itemize or not, and it's in addition to the existing extra standard deduction seniors already get. You also need a valid Social Security number, and leaving it off is treated as a math error the IRS can fix without sending a deficiency notice.

Notice what's missing from that list: any change to how benefits themselves are taxed. The new deduction lowers your overall tax bill, which is why so many retirees came away believing their benefits are now untaxed. But it is a deduction against your income—not an exclusion of your Social Security. If you have a pension, an IRA withdrawal, a part-time job, or investment income and you left your benefits off line 6b of your return, the IRS will still match the form and still propose tax under § 86. The deduction and the benefit tax are two separate things, and confusing them is exactly what produces these notices.

How § 86 Actually Works—In Plain English

Social Security isn't taxed the way wages are. Instead, § 86 includes a portion of your benefits in income—and the size of that portion depends on how much other income you have. There are two key numbers and one hard ceiling.

The ceiling first, because it's reassuring: the most that can ever be taxed is 85% of your benefits. Never 100%. A lot of people read "85%" and panic that they'll be taxed at 85 cents on the dollar. That's not it—85% is the cap on how much of the benefit gets counted as income, and that income is then taxed at your ordinary rate like everything else. Many retirees fall well below even the 85% tier.

To see where you land, the formula uses something usually called "combined income" (or "provisional income"). It's not a term on any form, but it's the number that decides everything:

Combined income = your other income + tax-exempt interest + one-half of your Social Security benefits

That "other income" is really your modified adjusted gross income (MAGI) for this purpose—and here's a surprise that catches a lot of people: tax-exempt municipal-bond interest counts. Interest that's tax-free as interest still gets added back in here and can push your benefits into taxability. Many disputes start exactly there.

Now compare your combined income to two thresholds set by your filing status:

Filing status	First threshold (base amount)	Second threshold (adjusted base)
Single / Head of Household / qualifying surviving spouse	$25,000	$34,000
Married filing jointly	$32,000	$44,000
Married filing separately, lived apart from spouse all year	$25,000	$34,000
Married filing separately, lived WITH spouse any part of the year	$0	$0

Below the first threshold: none of your benefits are taxable.
Between the two thresholds: up to 50% of your benefits become taxable.
Above the second threshold: up to 85% of your benefits become taxable.

Why More People Get Caught Every Year

Here's a fact that explains a lot of frustration: these thresholds have never been adjusted for inflation. The $25,000 and $32,000 figures were set in 1983; the $34,000 and $44,000 figures were added in 1993. They've been frozen ever since, while benefits and prices have risen for forty years. So a retiree who was comfortably below the line a decade ago can now sit above it on the same lifestyle—the line didn't move; everything else did. That's the structural reason an ever-larger share of retirees crosses these thresholds each year, and why these notices keep arriving.

The Married-Filing-Separately Trap

Look again at the last row of that table—it is the single most litigated § 86 fact, and it catches people completely off guard. If you are married, file separately, and lived with your spouse at any point during the year, your thresholds are both $0. That means up to 85% of your benefits are taxable from the very first dollar—there's no tax-free zone at all.

This is exactly what happened in Kelley v. Commissioner, T.C. Memo. 2021-2. Mr. Kelley, representing himself, was married and lived with his wife but filed separately. He received $20,646 in benefits and reported $0 as taxable. Because the married-filing-separately-living-together rule set his base amount at $0, the IRS taxed 85%—$17,549—and the Tax Court sustained it. The math simply wasn't in his favor, and the statute is unforgiving on this point.

If a notice taxing your benefits has you in this situation, the first thing to check is whether your filing status is actually correct—because for many people, it isn't the best choice. Whether you can file jointly, or qualify for a different status, is a real question worth examining; the marital-status and filing-status mechanics are owned by Head-of-Household Filing Status Disputes in Tax Court and Dependency Claim Disputes in Tax Court. The point here is narrow but vital: filing status drives the threshold, and the wrong status can cost you the entire tax-free zone.

The "Tax Torpedo": Why a Small Extra Bit of Income Hurts So Much

Because § 86 keys off your combined income, every extra dollar of other income can drag 50 to 85 cents of your benefits into taxable income along with it. Tax professionals call this the "tax torpedo." Within the phase-in range, the real (marginal) tax rate on, say, an IRA withdrawal can run far higher than your nominal bracket—because that one withdrawal is taxed and it makes more of your benefits taxable at the same time.

This is why the real culprit is usually the other income, not the benefits. A pension payment, an IRA or 401(k) distribution, a part-time wage, a capital gain, or even tax-exempt muni interest can cascade your benefits into tax. The Tax Court sees this mechanism directly—in Besaw v. Commissioner, T.C. Summary Op. 2025-8, a recent case where the taxpayer represented himself, an adjustment to the taxpayer's gross income triggered a "computational adjustment for Social Security" that changed because the other income changed. The benefits weren't really the issue; the income that pushed them over the line was.

That has a powerful flip side. If the other income that tipped you over wasn't actually as large as the IRS thinks—or wasn't fully taxable—then fixing that number fixes the Social Security tax automatically. When a distribution that pushed you over was really a tax-free rollover, or included after-tax basis, or shouldn't have been counted at all, knocking it down pulls your benefits back below the threshold too. If a retirement distribution is what put you over, that fight has its own home: Taxed on a Retirement Withdrawal? How To Fight a 1099-R Bill owns the basis, rollover, and distribution-taxability mechanics—start there for the "other income" piece, and let this guide handle the benefit formula.

SSI Is Never Taxable—SSDI Is

One distinction trips up a lot of people, and getting it wrong leads to needless worry or a needless return error.

Supplemental Security Income (SSI) is never taxable. SSI is a needs-based program funded from general revenue, not based on your work record. It isn't a "Social Security benefit" for § 86 purposes at all, and it doesn't generate an SSA-1099. If all you received was SSI, none of it goes on your return as taxable.
Social Security Disability Insurance (SSDI) is subject to § 86. SSDI is paid out of the same Social Security system as retirement benefits and is reported on an SSA-1099. It runs through the exact same formula above. People often hear "disability" and assume it's tax-free like SSI—it isn't. An SSDI recipient with other income can absolutely owe tax on those benefits.

(A narrow related point: if workers' compensation reduced—"offset"—your SSDI, the offset amount is treated as a Social Security benefit to that extent. It's a wrinkle worth knowing if your SSA-1099 reflects an offset.)

Got a Big Back Payment? The Lump-Sum Election Can Cut the Tax

If you received retroactive benefits in one year that were actually owed for prior years—common after a disability claim is finally approved, or a delayed award comes through all at once—a special rule can lower your tax. Under § 86(e), you can elect to figure the taxable part of that lump sum as if each year's share had been received in the year it was for, without amending any prior returns.

Why it helps: spreading the back payment across the years it belongs to often keeps you under the thresholds in each of those years, instead of stacking the whole sum into one year and blowing past the 85% tier. Box 3 of your SSA-1099 breaks the lump sum down by year so you can do this. (Lost the form? You can get a replacement SSA-1099 instantly from your free my Social Security account at ssa.gov or by calling 1-800-772-1213.) IRS Publication 915 walks through the worksheets, and you simply check the lump-sum-election box on Form 1040, line 6c. If a big retroactive award is part of your notice, this election is one of the most valuable moves available—test it before you accept the IRS's number. And if you already filed and paid without making the election—or overstated your taxable benefits in some other way—you can claim the refund by filing an amended return, generally within three years; see How To File an Amended Return.

One trap to flag: the lump-sum election lowers your § 86 tax, but it does not lower your household income for the Affordable Care Act Premium Tax Credit—the back benefits still count in full there. If you also have a marketplace-insurance issue, that interaction is covered in ACA Premium Tax Credit Disputes in Tax Court.

What You're Really Facing: The Full Exposure Picture

A § 86 notice is rarely just the tax on your benefits. Build the whole picture so nothing blindsides you—and so you can see what fixing the number is worth.

The deficiency itself. Income tax on the newly-included slice of benefits—up to 50%, then up to 85%, taxed at your ordinary rate. Thanks to the tax torpedo, a modest amount of other income can make this slice surprisingly large.
The accuracy-related penalty—20%. IRC § 6662 adds a penalty of 20% of the underpayment for a substantial understatement (broadly, an understatement over the greater of $5,000 or 10% of the correct tax). On a typical $3,000–$10,000 § 86 deficiency, that's roughly $600 to $2,000 before interest. In Besaw, the court sustained a § 6662 penalty of $906.60 on a $5,124 deficiency. There's a real defense, though—reasonable cause and good faith under IRC § 6664(c). If you genuinely believed the "no tax on Social Security" headlines and left your benefits off in good faith, that honest, reasonable mistake is exactly the kind of story reasonable cause is built for. And the IRS does drop the penalty when a taxpayer engages, as it did in Patrinicola v. Commissioner, T.C. Memo. 2023-16, where it conceded the penalty entirely. See How To Fight the IRS Accuracy Penalty.
Interest. Interest runs on the deficiency from the original due date of the return until it's paid under IRC § 6601, and it compounds daily. Unlike the penalty, interest cannot be waived for reasonable cause—which is one more reason to fix the number fast. On an older tax year, the interest can quietly add up to a meaningful share of the bill—and on a year that old, it's also worth checking whether the IRS is even still in time to assess (generally 3 years from when you filed; see Understanding IRS Statutes of Limitations). See How Interest Works on Your IRS Tax Debt.

The flip side of all this: because the penalty and interest are computed on the deficiency, shrinking the taxable benefits shrinks everything below them too. Win the benefit number and the penalty and interest follow it down.

A quick worked example to make it concrete. Suppose you're single, with a $30,000 pension and $20,000 in benefits, and you left the benefits off your return. Your combined income is $30,000 + $10,000 (half your benefits) = $40,000—above the $34,000 second threshold. Running the § 86 formula on those numbers makes $9,600 of your $20,000 in benefits taxable—just under half, not the full 85% ceiling. At a typical retiree's 12% rate, that $9,600 of newly-counted income is about $1,150 in tax. Add a 20% accuracy penalty (~$230) and a couple of years of daily-compounding interest, and the total climbs to roughly half again as much as the bare tax. But if part of that "$30,000 pension" was actually after-tax basis or a rolled-over amount, your combined income drops, fewer benefits are taxable, and the entire stack—tax, penalty, interest—comes down with it.

How To Verify and Rebut the IRS's Number

This is where § 86 cases are won. The formula is mechanical, so the dispute is really about the inputs. Every step here is something you can do yourself.

Pull your Wage & Income transcript. This shows the actual SSA-1099 the IRS received under your Social Security number—including the all-important box 5 (net benefits), which is the figure the formula uses. Confirm the IRS is working from the right benefit amount. You can pull this transcript yourself through IRS.gov; you don't need a practitioner. See How To Get and Read Your IRS Transcripts.

Recompute your own taxable amount with Pub. 915, Worksheet 1. IRS Publication 915 contains the official worksheet that produces the taxable number that belongs on Form 1040 line 6b (your total net benefits go on line 6a). It's a fill-in-the-blanks computation—line 1 is box 5 of your SSA-1099, and the final line is your taxable benefits, capped at 85%. Running it yourself produces the clean, documented number you put in front of the IRS. Pub. 915 even includes a short five-line "quick check" (Worksheet A) that can show, in a minute, that none of your benefits are taxable.

As you recompute, check the four inputs that decide these cases:

Is the SSA-1099 figure right? Compare box 5 on the transcript to your own records. If the benefit figure itself is wrong, that's a separate error to flag. (If box 5 is negative—you repaid more in benefits than you received during the year—none of your benefits are taxable, and a repayment over $3,000 may even produce a deduction or credit.)
Was the "other income" actually taxable? This is the big one. Was a pension or IRA distribution really fully taxable—or was it a rollover, a return of after-tax basis, or a qualified charitable distribution that shouldn't be in income at all? Knocking it down pulls your benefits back below the threshold. (Send the distribution piece to the 1099-R guide; this is the most common real issue.)
Is your filing status right? The married-filing-separately-living-together $0 trap, versus single or joint, can change everything.
Was tax-exempt interest handled correctly? It belongs in the formula once—not double-counted, and not ignored.

If retroactive benefits are sitting in box 3 of your SSA-1099, also test the § 86(e) lump-sum election before accepting the number.

Who has to prove what. In Tax Court the IRS's notice is presumed correct, and you carry the burden of showing it's wrong under Tax Court Rule 142(a) (Welch v. Helvering, 290 U.S. 111 (1933)). IRC § 7491 can shift that burden to the IRS if you produce credible evidence and meet your recordkeeping and cooperation duties—but you have to invoke it, so plan on the burden being yours and win it with documents. And if the SSA-1099 figure itself is what's wrong, IRC § 6201(d) can require the IRS to come forward with more than the bare information return once you raise a reasonable dispute and have cooperated—the same way it works for any 1099.

A Warning: Do Not Argue That the Tax Is Unconstitutional

When the math is against you, it's tempting to reach for a bigger argument—that taxing Social Security is "double taxation" (you already paid in through payroll taxes) or otherwise unconstitutional. Do not make this argument. It has lost every single time, and it can get you penalized for raising it.

The Tax Court has consistently upheld § 86 as constitutional—the lead authority is McAdams v. Commissioner, 118 T.C. 373 (2002). In Kelley, the case from the married-filing-separately trap above, the taxpayer argued that the $0 threshold violated due process and equal protection; the court rejected it under rational-basis review and sustained the full deficiency, collecting the long line of cases—including decisions affirmed by the federal courts of appeals—that have turned away the same challenge.

The bigger risk is this: the Tax Court can impose a penalty of up to $25,000 under IRC § 6673 for maintaining a frivolous position, and constitutional attacks on § 86 are squarely in frivolous territory. So you would be spending your one shot in court on an argument that cannot win and that can add to your bill. Put your energy into the numbers instead—that's where these cases are actually won.

What To Do Now

If a notice taxing your Social Security benefits is in front of you, here's the sequence:

Identify the deadline on the notice. If it's a 90-day letter (Notice of Deficiency), you have 90 days to file in Tax Court (150 days if addressed outside the US). Look for the exact "last day to file a petition" date printed near the top of the first page—that is your hard deadline, and it cannot be extended. If it's a CP2000, look instead for the response-by date, and you can still resolve it before any deficiency issues—see How To Respond to a CP2000 Notice.
Pull your Wage & Income transcript and confirm the exact SSA-1099 box 5 figure the IRS has under your number.
Recompute your taxable benefits with Pub. 915 Worksheet 1, using your real income. Check the four inputs: the benefit figure, whether the other income was truly taxable, your filing status, and tax-exempt interest.
Test the § 86(e) lump-sum election if you received a retroactive or back-paid award.
Decide whether to petition Tax Court. A timely petition preserves your right to fight before paying. Filing is $60, with a waiver available. Most § 86 deficiencies fall under $50,000, so they qualify for the simpler "S case" procedure—Besaw was one. See How To File Your Tax Court Petition.
Expect to resolve before trial. Most (76%) of Tax Court cases close by formal settlement, and more than 99% close without a trial on the merits. Because § 86 is arithmetic, these cases routinely settle the moment you put a corrected, documented worksheet in front of the IRS—exactly the dynamic in Patrinicola, where engaging cut the proposed adjustment by most of its value and erased the penalty. See How To Settle Your Tax Court Case.
Do not raise constitutional or "double taxation" arguments. They lose and can draw a § 6673 frivolous-position penalty.
If you missed the 90-day deadline and the deficiency was assessed, audit reconsideration is the fallback.
If the number turns out to be right and you can't pay it, you still have options—an installment agreement, currently-not-collectible status, or an offer in compromise. Don't ignore the bill; see How To Resolve Your IRS Tax Debt.

Two more things to plan for. First, a change to your federal income usually changes your state tax too, since most states start from your federal numbers. Second, watch the Medicare knock-on: Part B and Part D premiums are set by your income from two years earlier (the IRMAA surcharge), so a one-time spike—a big distribution or a lump-sum award—can raise those premiums down the road. Fixing an overstated income number can help on more than one front.

Around 89% of petitioners represent themselves, though the win rate trails represented petitioners (about 12% pro se versus about 23% represented in the most recent NTA data). These § 86 cases—modest dollars, often a retiree on a fixed income, and a problem that comes down to recomputing one worksheet—are close to a textbook fit for free help. If your income is at or below 250% of the poverty line and your dispute is at or below $50,000, a Low Income Taxpayer Clinic may handle your Tax Court case at no cost. See also When To Get Professional Help With Your Tax Dispute.

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This article is for informational purposes only and does not constitute legal or tax advice. For advice specific to your situation, consult a qualified tax professional or attorney.