47 0 0 0 13 6. You’re one of the shrinking how to invest lump sum pension payout of Americans who have earned the right to a pension—guaranteed income for life for you and maybe for your spouse as well. Just make sure you don’t give it up too easily.

Up to half of companies with pension plans, say experts, give workers the option of taking their pension as a lump sum. Boeing and Hewlett-Packard, either have just made or will soon make pension buyout offers to vested former employees, benefits firm Aon Hewitt reported earlier this year. Lump-sum checks, often in the hundreds of thousands of dollars, are tempting. Fifty-eight percent of employees take buyouts, and the share taking the lump-sum option at retirement is likely higher, says Aon Hewitt consultant Ari Jacobs. Pension industry experts and consumer advocates, however, say that for most workers the traditional pension is a better deal. If you or your spouse is in good health and has a family history of longevity, lean toward taking the monthly pension.

The advantages: The money lasts for life. 65-year-olds do—you’ll still be getting that check. And, in exchange for smaller benefits, your spouse can continue to receive half or often all of those monthly payments after your death. So if you’re a man and your wife survives you—on average, she will—she’ll get cash for life too.

But even if you’re the next Warren Buffett, you’d likely get less each month than you would from a pension. Why is the lump-sum income so low? Flying solo, you have to make sure your money lasts a full 20 or 25 years. But in a group plan, a lot of people will live shorter lives, so less money has to be reserved for them. The result is more generous monthly payouts for everyone, says Robert Goldbloom, a principal at pension consultant Penbridge Advisors. If you’re in poor health and don’t have to provide for a spouse, the math favors the lump sum.

Given a life expectancy of a decade or less, you’d have more than enough to duplicate a pension. A lump sum also makes sense if you have no cash in the bank or investments you can tap for emergencies. You could keep part of that money in the bank for urgent needs, and live off the rest. Should you be lucky enough to live comfortably off other sources of income, you could take the money and invest it aggressively to maximize a possible inheritance for your beneficiaries.