How Social Security Benefits Are Taxed — and How Married Couples Can Minimize the Impact

The Basics: Not All Benefits Are Taxed

Social Security benefits were not taxable at all until 1984. Today, depending on your total income, anywhere from 0% to 85% of your Social Security benefits may be included in your federal taxable income. The actual percentage is never more than 85% — Congress specifically designed the law so at least 15% of benefits remain tax-free regardless of income.

The key number is your "combined income" (also called "provisional income"), which the IRS uses to determine how much of your benefits are taxable.

How to Calculate Your "Combined Income"

Combined income = Adjusted Gross Income + Nontaxable interest + 50% of Social Security benefits

Notice that you include half of your Social Security benefits in the calculation — even though those benefits may ultimately be tax-free. This is the formula the IRS uses to determine whether you cross the thresholds below.

The Thresholds for Married Filing Jointly

The Thresholds for Married Filing Separately

Here's where filing status creates a dramatic difference: if you file separately and lived with your spouse at any point during the year, the first threshold is effectively $0. This means virtually all of your Social Security income becomes taxable immediately — one of the harshest MFS penalties for retirees.

However, if you were legally separated or lived completely apart from your spouse for the entire year, the standard single-filer thresholds apply: $25,000 and $34,000. This is a narrow exception that benefits some couples in unusual circumstances.

A Real-World Example

Let's say a married couple receives $40,000 in combined Social Security benefits. They also have $35,000 in pension income and $5,000 in interest income.

• AGI (before SS): $35,000 + $5,000 = $40,000
• 50% of SS: $20,000
• Combined income: $40,000 + $20,000 = $60,000

Since $60,000 exceeds $44,000, up to 85% of their $40,000 benefits ($34,000) may be included in taxable income. This means paying federal income tax on up to $34,000 of Social Security benefits — a significant and often unexpected tax burden for new retirees.

Strategies to Reduce Taxable Social Security

The goal is to manage your combined income so it stays below the thresholds — or at least in the lower tier. Here are the most effective strategies:

1. Draw Down Traditional IRA / 401(k) Before Claiming Social Security

Every dollar you withdraw from a traditional retirement account after age 59½ adds to your combined income, potentially pushing more SS benefits into taxable territory. If you can afford to, withdraw from tax-deferred accounts in the years before you begin Social Security — while your combined income is lower — and convert some to Roth accounts. Once you start Social Security, Roth withdrawals don't count toward combined income at all.

2. Roth Conversion Strategy

Convert traditional IRA/401(k) funds to Roth accounts in low-income years before you start claiming Social Security or before Required Minimum Distributions (RMDs) begin at age 73. After conversion, future distributions from Roth accounts are tax-free and do not count toward combined income. This is a multi-year strategy that requires careful planning.

3. Manage Investment Income

Interest, dividends, and capital gains all count toward combined income. Consider holding bonds inside tax-advantaged accounts (IRAs) rather than taxable brokerage accounts, and favor qualified dividends and long-term capital gains which are taxed at lower rates.

4. Qualified Charitable Distributions (QCDs)

If you're age 70½ or older and have a traditional IRA, you can make direct charitable contributions of up to $105,000 per year directly from your IRA to a qualified charity (a Qualified Charitable Distribution). The amount transferred is excluded from your taxable income entirely — and crucially, it doesn't count toward your combined income for the SS calculation. This strategy is especially powerful for charitably inclined retirees.

5. Delay Social Security — But Carefully

Delaying your Social Security claim past age 62 increases your monthly benefit by up to 8% per year (until age 70). Delaying also means that for those years, you have no SS benefits to be taxed — potentially giving you room to do Roth conversions or draw down tax-deferred accounts at lower tax rates. The tradeoff is fewer years of receiving benefits overall.

6. Consider Filing Status Impact

As shown above, MFS filers who live together face a $0 threshold — making essentially all Social Security income taxable. If one or both spouses receive significant SS benefits, filing jointly almost always produces a better tax outcome in retirement. Our Tax Comparator can model this for you.

State Taxes on Social Security

In addition to federal taxes, some states also tax Social Security benefits. As of 2025, about 11 states tax SS benefits to some degree. If you live in one of these states, your total tax burden on Social Security may be higher than federal calculations alone suggest. Check your state's specific rules or consult a local tax professional.