FHA's Home Equity Conversion Mortgage (HECM) carries the lowest interest rate but also has the lowest maximum values. These vary by county and range from $154,896 to $280,749. (The FHA county limits can be found at https://entp.hud.gov/idapp/html/hicostlook.cfm.) Fannie Mae's Home Keeper has a higher interest rate but its maximum value limit is a uniform $322,700.

You have a house worth $300,000, well above the FHA maximum of $184,666, which is tied to the median home value in your county. The maximum HECM credit line available to you is $120,252 and it is based on $184,666 rather than $300,000. (The credit line can be withdrawn immediately as a lump sum, or over time as you prefer).

Your credit line under Fannie Mae's Home Keeper program is higher, $132,753, because it is based on $300,000, the actual value of your home. The higher value more than offsets the higher interest rate under this program.

Instead of taking a credit line, you could elect to receive a monthly payment for as long as you live in the house. You could draw $883.16 under HECM and $1,162.06 under Home Keeper.

The other side of the coin is that because of the larger draw and the higher interest rate, you will accumulate more debt under Home Keeper. When you reach 95, assuming you take the monthly payments, you will owe $363,860 under Home Keeper but only $252,868 under HECM.

If you have no heirs that you are concerned about and want the largest possible monthly payment starting immediately, Home Keeper would be the right choice. You could receive the $1,162.06 under Home Keeper for as long as you live in your house. The payments stop if you sell the house, or have to be in a nursing home for 12 consecutive months.

An alternative is to withdraw $132,753 as a lump sum and use it to purchase an immediate annuity from a life insurance company. The advantage of purchasing an annuity is that it probably would be larger than $1,162.06, and it would continue for life. The disadvantage is that the annuity is only as good as the life insurance company from which you buy it, so limit yourself to a highly rated company. You can find immediate annuity quotes on www.immediateannuity.com, which also shows the quality ratings of each company.

On the other hand, you might want to preserve as much equity as possible, either to leave in your estate or because you might sell the house at some point. In such case, assuming you can make do with the smaller payment, HECM is the better choice because of the smaller buildup of debt. You should consider the same alternative of withdrawing a lump sum and purchasing an immediate annuity.

If your immediate need for cash is small but you anticipate that it will grow, HECM may be the better choice regardless of your attitude toward preserving equity. The credit line grows under the HECM program but not under Home Keeper. If you use only 10 percent of the HECM line at the outset, the unused portion will be as large as the Home Keeper line in about 5 years.

If you have no immediate need for funds, defer a selection until you do have a need. The passage of time increases the amounts you can draw under both programs, since you become older and the loan limits are raised every year. But don't use this as an excuse to procrastinate. Do your homework and be ready.

Under no circumstances should you draw money on any reverse mortgage in order to invest it. There are no safe investments available that pay a return higher than the cost of the reverse mortgage to you. Draw to consume, not to invest.

The writer is Professor of Finance Emeritus at the Wharton School of the University of Pennsylvania. Comments and questions can be left at www.mtgprofessor.com.

Copyright 2003 Jack Guttentag