Income and Assets · Retirement income

Excess contributions and their tax treatment

The tax on an excess contribution is not a one-off penalty. It is imposed for each taxable year the excess is still in the account, so a mistake made once and never corrected is charged again every December. That recurrence, rather than the rate, is what makes the topic worth getting right, and it is what most clients do not realise.

The rule

The charge and its ceiling. For an individual retirement account or annuity, an Archer MSA, a § 403(b)(7)(A) custodial account, a Coverdell education savings account, a health savings account or an ABLE account, there is imposed for each taxable year a tax equal to 6 percent of the excess contributions, determined as of the close of the taxable year (IRC § 4973(a)(1)–(6)). The tax may not exceed 6 percent of the value of the account at that date, and it is paid by the individual, not by the custodian.

What counts as excess. For IRAs the term means the excess of the amount contributed for the year — excluding a contribution to a Roth IRA and excluding rollover contributions described in §§ 402(c), 403(a)(4), 403(b)(8), 408(d)(3) or 457(e)(16) — over the amount allowable as a deduction under § 219, plus the prior year’s excess carried forward (IRC § 4973(b)(1), (2)).

The carryforward can be absorbed, not just withdrawn. The prior year’s amount is reduced by distributions included in gross income under § 408(d)(1), by distributions to which § 408(d)(5) applies, and by the excess of the maximum § 219 deduction for the year over the amount actually contributed (IRC § 4973(b)(2)(A)–(C)). That last limb is the useful one: an uncorrected excess is soaked up by simply contributing less than the limit in a later year.

Timely correction removes the problem entirely. A returned contribution escapes the § 408(d)(1) inclusion rule if the distribution is received on or before the due date of the return including extensions, no § 219 deduction is allowed for the contribution, and the distribution is accompanied by the net income attributable to it (IRC § 408(d)(4)(A)–(C)). That net income is treated as earned and receivable in the year the contribution was made, not the year of withdrawal.

Late correction is narrower. Where the aggregate non-rollover contributions for the year do not exceed the § 219(b)(1)(A) dollar amount, a distribution of the excess after the § 408(d)(4) date is still outside § 408(d)(1), but only to the extent no deduction was allowed (IRC § 408(d)(5)(A)). Net income need not accompany it — the trade-off is that the excise tax has already run for the intervening years.

Excess elective deferrals are a different regime with different dates. Elective deferrals above the applicable dollar amount are included in gross income (IRC § 402(g)(1)(A), (B)). To correct, the individual may allocate the excess among the plans by 1 March following the close of the taxable year, and each plan may distribute its allocated share with allocable income by 15 April following that close (IRC § 402(g)(2)(A)(i), (ii)) — a distribution the paragraph permits notwithstanding any other provision of law. Note that these are not the return due date: they are fixed calendar dates, and an extension does not move them.

Current figures

How it works in practice

The commonest excess is not an over-contribution at all — it is a Roth contribution made by someone whose income turned out to exceed the § 408A(c)(3) range. The client contributed a permitted amount in January and became ineligible by December, and nothing tells them until the return is prepared.

Once identified, the first question is the date. Before the extended due date, § 408(d)(4) is available and is much the better route: the contribution comes back with its attributable net income, no deduction having been claimed, and the excise tax never attaches. Filing an extension is therefore worth doing on its own merits here, because it buys six months of correction window even for a return that will be filed in April.

After that date, weigh withdrawal against absorption. Section 4973(b)(2)(C) reduces the carried excess by the unused § 219 deduction for a later year, so a client who simply skips or reduces the next year’s contribution eliminates the excess without withdrawing anything — at the cost of the excise tax for the intervening years. Where the excess is small and the client wants to keep contributing, withdrawing is usually cheaper; where it is large and they were going to stop anyway, absorption may be better.

For excess deferrals, act on the calendar rather than the return. The 1 March allocation and 15 April distribution dates in § 402(g)(2) are fixed, apply across multiple employers, and are the client’s responsibility rather than the plan’s — a taxpayer who changed jobs mid-year and deferred fully at both employers is the classic case, and no single plan will notice.

How this has changed

The mechanics are old and have not moved. The rate in § 4973(a), its account-value ceiling, the three conditions in § 408(d)(4) and the two dates in § 402(g)(2) are all statutory and unchanged.

What does move is the limits against which an excess is measured, and there the statute is unreliable on its face. Section 402(g)(1)(B) still prints an applicable dollar amount fixed decades ago; the figure actually in force for 2026 is several times that, announced in the annual notice. Section 219(b)(5) and the § 408A(c)(3) Roth ranges are the same. So the rule creating an excess is stable while the number defining it is not — which means a source can be entirely correct about the mechanics and produce the wrong answer.

The one structural point worth watching is the breadth of § 4973(a). It now reaches six kinds of account, including health savings accounts and ABLE accounts added long after the section was written. Material that treats the 6 percent charge as an IRA rule is describing the section as it was, not as it is — and an excess HSA contribution behaves the same way, recurring annually until corrected.

Exam focus

Know that the tax is imposed for each taxable year the excess remains, and that it is capped by the account value. Expect a question testing whether it is a single charge.

Know the three conditions in § 408(d)(4) and that the deadline includes extensions. Expect facts turning on whether correction was timely.

Know that the net income attributable is taxed in the contribution year rather than the withdrawal year.

Know that § 4973(b)(2)(C) lets a later under-contribution absorb an earlier excess, and know the two fixed § 402(g)(2) dates for excess deferrals, which an extension does not move.

Check yourself

1. A taxpayer made a $5,000 excess IRA contribution four years ago and has done nothing about it. How much excise tax is owed?

Answer: 6 percent of the excess for each of the four years, subject to the cap. IRC § 4973(a) imposes the tax for each taxable year, measured on the excess contributions determined at the close of that year, and limits it to 6 percent of the account value at that date. It is not a one-time penalty, and it continues until the excess is withdrawn or absorbed.

2. What three conditions must be met for a returned contribution to escape inclusion under IRC § 408(d)(1)?

Answer: the distribution must be received on or before the due date for the return including extensions; no deduction may be allowed under § 219 for the contribution; and the distribution must be accompanied by the net income attributable to the contribution (IRC § 408(d)(4)(A)–(C)). All three are required, and the net income is treated as earned in the year the contribution was made.

3. A taxpayer with an uncorrected excess from a prior year contributes $3,000 less than the maximum this year. What is the effect?

Answer: the carried excess is reduced by $3,000. IRC § 4973(b)(2)(C) reduces the prior year’s amount by the excess of the maximum § 219 deduction for the taxable year over the amount actually contributed. So under-contributing absorbs an earlier excess without any withdrawal — though the excise tax for the years the excess was outstanding is still owed.

4. A taxpayer deferred the maximum at two employers after changing jobs. By when must the excess be corrected?

Answer: the individual may allocate the excess deferrals among the plans not later than the 1st March following the close of the taxable year, and each plan may distribute the allocated amount with allocable income not later than the 1st April 15 following that close (IRC § 402(g)(2)(A)(i), (ii)). These are fixed dates rather than the return due date, and filing an extension does not move them.