Non-Taxable Income

The tax code treats everything you receive as income unless a specific provision excludes it. Non-taxable income is the list of those exclusions, written one section of the code at a time, which is why each item comes with its own limits and exceptions.

Three different ideas hide behind the phrase “tax-free”, and mixing them up causes most planning errors. Excluded income, such as a gift or a life insurance payout, never becomes taxable income. Tax-deferred money, such as a traditional 401(k) contribution, skips tax now and is taxed on the way out, so it isn’t non-taxable at all. And the standard deduction shelters income from the brackets without excluding it: income it covers still counts in your adjusted gross income, while excluded income never gets there.

Non-taxable at the federal level doesn’t settle state tax, either. States follow most federal exclusions but not all of them. Interest on another state’s municipal bonds is usually taxed by your own state, while Treasury interest is the reverse: taxable federally, but exempt from state and local income tax.

Most non-taxable income falls into a handful of families. Knowing which family an item belongs to tells you where its limits are likely to be.

Personal transfers are the largest. Property you receive as a gift, bequest or inheritance isn’t income to you, and neither is child support or alimony under a divorce or separation agreement signed after 2018. Insurance and injury payments come next: life insurance death benefits, workers’ compensation, and damages for a physical injury or sickness.

Employers provide several: health coverage paid for by the employer, group-term life insurance on up to $50,000 of coverage, and employer contributions to a health savings account. Government programs add welfare and public assistance, veterans’ benefits and disaster relief payments, and for a degree candidate, the part of a scholarship spent on tuition, fees, books and required supplies is excluded too.

The last family is the one planners use deliberately: income that is tax-free because of how it was saved or held. Qualified Roth IRA withdrawals, HSA withdrawals for medical care, 529 withdrawals for education, interest on municipal bonds, and up to $250,000 of gain on the sale of a main home ($500,000 on a joint return) under the home sale exclusion all fall here. Getting your own money back is never income either: the cost basis returned when you sell an investment isn’t taxed, only the gain.

Some non-taxable income still has to be reported, and the numbers feed other formulas. Tax-exempt interest goes on Form 1040 line 2a, and Social Security benefits are entered in full before the taxable part is worked out.

The most important of those formulas is provisional income, which decides how much of your Social Security is taxable. It adds tax-exempt interest back in, so municipal bond interest that escapes tax itself can make more of your benefits taxable, as the example below shows. Medicare’s IRMAA surcharges use AGI plus tax-exempt interest, read from the return two years earlier. For the marketplace premium tax credit and Medicaid, MAGI adds back untaxed foreign income, the non-taxable part of Social Security and tax-exempt interest.

Qualified Roth withdrawals are the cleanest non-taxable income a retiree can have, because they appear in none of these formulas. A dollar from a Roth IRA doesn’t raise the taxable share of Social Security, doesn’t move you toward an IRMAA tier and doesn’t shrink a premium credit. That is a large part of why Roth money is worth more in retirement than its balance suggests.

The exclusions are narrower than their nicknames. Most costly errors come from treating the whole of a payment as tax-free when only part of it is, or from forgetting that an exclusion covers the money itself but not what that money earns afterward. They tend to surface years later, when an inherited account is emptied, a Roth is tapped early, or a notice arrives for interest nobody reported. A few come up again and again: