Lump Sum vs. Monthly Break-Even Calculator

This calculator shows the investment return a lump sum needs to match your monthly pension, and how long the money lasts.

How a Pension Lump Sum Is Calculated

A lump sum is today’s value of every monthly check you are expected to receive, discounted with interest rates and weighted by how long people your age are expected to live.

Three ingredients set the number: your monthly benefit, a mortality table, and interest rates. The IRS publishes three “segment rates.” The first discounts payments in roughly the next five years, the second covers years five through twenty, and the third covers everything after that.

Under IRC §417(e)(3), a qualified defined-benefit plan’s lump sum generally can’t be smaller than the present value figured with those IRS rates and the IRS mortality table. The plan pays the greater of that floor and its own actuarial-equivalent amount.

Lump sum vs. monthly pension, side by side

Why Many 2027 Lump Sums Are Smaller

All three IRS segment rates were higher in August 2026 than in August 2025, and higher rates mean a smaller lump sum for the same monthly pension.

The first segment rose from 4.20% to 4.65%, the second from 5.29% to 5.75%, and the third from 6.08% to 6.73%.

Your plan doesn’t use today’s rate. It picks a lookback month and holds that month’s rates for a stability period. A calendar-year plan with an August lookback prices 2026 starts with August 2025 rates and 2027 starts with August 2026 rates.

For an August-lookback, calendar-year plan at age 65, the rate rise alone trims roughly 4% from the lump sum. That figure is specific to plan design and age, not a universal number.

Does Retiring in December Matter for You?

It matters only if your plan is a traditional pension that resets its rates on January 1 and you can still start, and be paid, before the year ends.

Several things have to line up. Your plan must use rates tied to the calendar year. Your lookback month must be one where rates rose. Your election window must still be open.

The election notice is generally provided 30 to 180 days before the annuity starting date, and in some cases the minimum can be waived down to 7 days. Plans set their own election deadlines, so the date that counts is your plan’s election window and annuity starting date, not simply December 31.

A different start date also changes your monthly pension, through your age, service, and any early-retirement reduction. A rate difference alone isn’t a reason to start earlier or later. Get both options in writing for each date.

The Break-Even Math

The break-even return is the annual investment return at which the lump sum exactly pays the same monthly amounts through the age you plan for.

Here is an illustration, not a prediction. A $150,000 lump sum against $1,000 a month starting at 65, planned to age 90, has a break-even return of about 6.6% a year. Invested at 5% minus 0.20% in fees, that lump sum would run out at about age 84.

Three things move the answer. A longer planning age raises the return you need. A cost-of-living adjustment raises it a lot, but most private pensions have none. Market losses early in retirement hurt more than the same losses later, which this calculator doesn’t model.

Comparing against an insurer quote shows what your lump sum would buy on the open market. Higher rates tend to raise those quotes. Commercial annuities are covered in Annuities: Fixed, Variable & Indexed.

To test whether a lump sum could last through your whole plan, see the stress-test tool in Can AI Plan Your Retirement. For the bigger picture, see Retirement Income Planning, How Much Money Do You Need to Retire, and Retirement Withdrawal Order.

What You Give Up With a Lump Sum

You give up lifetime income that can’t run out, the survivor pension, and the plan-level protection of the Pension Benefit Guaranty Corporation (PBGC).

Longevity insurance. A pension keeps paying however long you live. A lump sum only pays as long as the money lasts and your spending allows.

Survivor benefit. A joint-and-survivor pension continues to a spouse. A lump sum leaves whatever remains, which may not match what a survivor needs.

PBGC protection. PBGC guarantees benefits up to legal limits, but only if a single-employer plan ends underfunded and PBGC becomes trustee. Once a lump sum is paid and rolled over, it is no longer a pension benefit, so PBGC does not guarantee it. For plans ending in 2027, the maximum at 65 is $8,113.64 a month for a straight-life annuity and $7,302.28 for a joint-and-50% survivor annuity, up 4.16% from 2026. Most retirees’ benefits fall below these limits.

Risk-transfer nuance. If your plan buys a group annuity from an insurer, protection generally shifts from PBGC to state guaranty associations. Their limits vary by state, so ask which state’s association would apply. See NOLHGA for background.

What You Give Up With the Monthly Pension

You give up flexibility, most of the legacy value, and, in most private plans, inflation protection.

Flexibility. The schedule is fixed. You can’t take extra in a bad year or fund a large expense from the pension itself.

Legacy. A single-life pension usually ends at death. Survivor or guarantee options can change that, at a lower monthly amount.

Inflation. Most private-sector pensions have no cost-of-living adjustment, so purchasing power can erode over a long retirement.

Employer risk above PBGC limits. If the plan fails underfunded, the part of a very large pension above the PBGC maximum may not be paid.

To see how a pension fits with Social Security, read When to Take Social Security.

Married? The Spousal Consent Rule

If you are married, the default pension form is a qualified joint and survivor annuity, and giving it up generally requires your spouse’s written consent.

Taking a lump sum waives the survivor annuity, so consent applies to it. The plan will explain your joint-and-survivor options and their monthly amounts, so ask for each in writing.

Talk through survivor income before you sign, and check who is named as beneficiary on any IRA you roll the money into.

Taxes: Rollover, 20% Withholding, Age 55, IRMAA

A direct rollover keeps the whole lump sum tax-deferred, while taking cash triggers mandatory 20% federal withholding and a taxable bump in income.

Direct rollover. The plan sends the money straight to an IRA or another employer plan. No withholding applies. See How to Roll Over a 401(k) to an IRA for the steps, which work similarly here.

Before 59½. Cash taken before 59½ generally adds a 10% additional tax unless an exception applies. The separation-from-service-at-55 exception applies to distributions from the employer plan, but you lose it once the money is rolled to an IRA. See The Rule of 55.

Bracket and IRMAA. Cash in a single year can push you into a higher bracket and raise your Medicare premiums two years later through IRMAA. See IRMAA Brackets. After a rollover, required distributions apply later; see RMD Rules.

Sources: IRS Publication 575 and IRS Topic 558.

Buyout Offers: When Your Employer Offers a Lump Sum Window

Employers offer lump sum windows to shrink pension obligations and the per-participant premiums they pay PBGC, which is a business reason, not a verdict on your best choice.

Read the packet for the deadline, the rates and month used, the monthly alternative, and whether the window price differs from normal lump sum pricing. Ask whether the plan is also considering a pension risk transfer.

Windows usually have firm deadlines and elections are generally irrevocable once the lump sum is paid. Get everything in writing and take the time you need.

Questions to Ask Before You Sign

These nine questions pull out the numbers and dates that decide your choice.

1. Which interest rates and month (lookback) does the plan use for lump sums, and what is the stability period?
2. What would my lump sum be for an annuity starting date of [month/year] vs. [later month/year]?
3. Is my lump sum the 417(e) minimum or the plan’s own factors (whichever is greater)?
4. What is the election deadline, and when will I receive the election notice?
5. What are my joint-and-survivor options and their monthly amounts?
6. Does the pension have any COLA?
7. Can I do a direct rollover to an IRA or my new employer’s plan?
8. Is the plan considering a pension risk transfer to an insurer?
9. Please send everything in writing.

A fee-only fiduciary can review your numbers; see Fiduciary vs Financial Advisor.

FAQ

Should I take my pension as a lump sum or monthly payments?

There is no one right answer. It depends on your health, other income, survivor needs, comfort with investing, and your plan’s numbers. Use the break-even calculator and your plan’s own figures.

How is a pension lump sum calculated?

It is the present value of your future monthly pension, using interest rates and a mortality table. Qualified plans must pay at least the 417(e) minimum.

Why is my 2027 pension lump sum smaller?

If your plan prices 2027 starts with August 2026 rates, those rates are higher than August 2025’s, which lowers the present value for the same pension.

What is a lookback month?

It is the month whose IRS segment rates your plan uses to price lump sums for the following stability period.

Will retiring in December 2026 get me a bigger lump sum?

Possibly, if your plan resets rates on January 1 and you can still start and elect on time. Your monthly pension also changes with the date, so compare both options.

Do cash balance plans change with interest rates?

Generally the lump sum is your account balance, so the IRS rate change doesn’t shrink it the same way.

Do government pensions use the same rules?

Government plans are generally not required to follow the 417(e) rules, so they follow their own plan terms. Ask for your plan’s factors.

Is a smaller lump sum always a bad deal?

No. Higher rates also make monthly pensions and insurer annuities more valuable relative to a lump sum, so the comparison shifts both ways.

What return do I need to beat my pension?

The calculator above solves for it. It depends on the lump sum, the monthly amount, your start age, the planning age, and any COLA.

Does PBGC protect my pension?

For single-employer plans that fail underfunded, up to legal limits. It doesn’t guarantee a lump sum once paid and rolled over.

What is the PBGC maximum guarantee for 2027?

For plans terminating in 2027, $8,113.64 a month at 65 for a straight-life annuity and $7,302.28 for joint-and-50% survivor. It is lower at younger ages (see Table 5).

What happens if my pension is transferred to an insurance company?

Protection generally shifts from PBGC to state guaranty associations, whose limits vary by state.

Does my spouse have to agree to a lump sum?

If you are married, generally yes. Waiving the survivor annuity requires written spousal consent, witnessed by a notary or plan representative.

How do I avoid the 20% withholding?

Choose a direct rollover to an IRA or another employer plan.

Can I roll my pension into an IRA?

Generally yes, if you take the lump sum. A direct rollover is the cleanest route.

Is there a penalty for taking a lump sum before 59½?

Cash taken before 59½ generally carries a 10% additional tax unless an exception applies. A rollover avoids it.

Will a lump sum raise my Medicare premiums?

Taking it as cash can raise your income enough to trigger IRMAA two years later. A direct rollover doesn’t add taxable income that year.

Can I change my mind after electing?

Plans often allow changes until the annuity starting date, but once the lump sum is paid or payments begin, the choice is usually irrevocable. Check your plan.