If a defined-benefit (DB) pension offers a choice between a lump sum and a monthly annuity, first confirm that both options are actually available under the plan and which benefits each amount includes. A lump sum is not an account balance equivalent to the monthly lifetime pension. One is a one-time amount calculated as a present value; the other is a stream of payments under plan terms. This article explains U.S. employer DB plans and part of the federal calculation framework, not an individual financial recommendation.

Conceptual comparison of a defined-benefit pension lifetime monthly payment stream and a one-time lump sum

The options shift timing and risk

A lump-sum election generally pays an amount set by the plan and gives up the monthly pension associated with that benefit. An annuity may pay for the participant’s life or continue partly to a spouse or beneficiary under a joint-and-survivor form, depending on the plan’s menu. Compare the actual proposal: monthly amount, start date, survivor benefit, and early- versus normal-retirement conditions. Labels alone do not show whether two options cover the same benefits.

A lump sum can offer flexibility for a large expense, coordinating other income, or leaving unspent assets to heirs. It also transfers investment, withdrawal, longevity, and money-management risks to the recipient. A plan annuity can share longevity risk through scheduled lifetime payments, but the initial amount may differ with a survivor election or cost-of-living provision. Neither form is automatically better. Separate household income, essential costs, health and caregiving needs, and tolerance for investment risk before comparing.

How the lump sum is calculated and where Section 417(e) fits

U.S. Internal Revenue Code §417(e)(3)(D) concerns interest and mortality assumptions used for minimum-present-value calculations for certain DB benefits. The IRS publishes three segment rates by month and plan year. Those rates are inputs to a rule-defined calculation; they are not an investment return a retiree can expect to earn, nor one market rate that directly prices every plan’s annuity.

A lump sum discounts future benefits to a present value, so the accrued benefit, payment timing, mortality and interest assumptions, plan document, and applicable law can affect the offer. IRS tables change by month. The plan documents and calculation date determine which month and plan-year rules apply to an individual proposal. Do not compare an old rate table or a generic calculator directly with a current offer. Ask the administrator in writing for the valuation date, assumptions, and any supplemental or survivor benefits included or omitted.

Compare the household, not just a headline amount

Request the single-life and joint-and-survivor monthly figures and identify how the survivor percentage changes the payment. Add Social Security, other pensions, savings, and essential expenses to a monthly cash-flow view. For a lump-sum scenario, list tax treatment, rollover eligibility, investment and management costs, withdrawal assumptions, and the effect of a poor market sequence as separate assumptions. Tax rules depend on current law and personal circumstances; the 2016 SOA brief is not a source for 2026 tax rules.

Survivor protection, inheritance, inflation, longevity, and liquidity are different goals. Compressing them into one expected-return comparison can hide who bears each risk. Keep the plan’s promised payments separate from assets the retiree must invest and manage, and show what happens if key assumptions are wrong.

Expert perspective: separate a current rate table from an older decision guide

The IRS table supplies month- and plan-year-specific inputs for §417(e) minimum-present-value calculations. The Society of Actuaries’ “Lump Sum or Monthly Pension” decision brief is explicitly dated May 2016. Its explanation that mortality and interest assumptions affect a lump sum, and its discussion of longevity and investment trade-offs, can inform the conceptual comparison. Its period-specific tax, regulatory, and Social Security details should not be presented as current rules.

The PBGC’s page describes benefit choices in the specific circumstance that PBGC takes over a plan. It does not establish the same lump-sum eligibility or election terms for every employer plan. Check the summary plan description, the individual benefit offer, marital status, and applicable law. This guide organizes questions to ask; it does not recommend which option a reader should elect.

Questions to resolve before electing

Ask the plan administrator for the total monthly amount under each payment form, survivor percentage, cost-of-living terms, lump-sum valuation date and §417(e) assumptions, benefits excluded from the offer, the deadline and whether an election can be changed, and tax or rollover information. Separately confirm whether the plan is covered by PBGC and what limits apply. Do not decide from a single calculator’s present-value result while these terms remain unclear.

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