One way to save for retirement is to make regular contributions into a tax-deferred annuity, sold by insurance companies. But thousands of people who started these plans many years ago have come to regret them.

Old annuity plans may still be paying 3 to 4 percent interest on long-time deposits. New plans, on the other hand, pay 9 1/2 to 10 percent. Today's yields still fall behind inflation, but they're not the disgrace that the old rates are.

If you have already retired and converted your annuity savings into a lifetime income, you're stuck. But if those savings are still building up in the annuity, there's no need to suffer in silence. You can strip the money out of the old, inefficient plan and transfer it to something better.

To find a good annuity, annuity specialist Joe Mintz of Dallas advises that you call several insurance agents and tell them you want a plan with a high return.

But don't be mislead by quoted interest rates. You might deposit $1,000 into a 9 1/2 percent annuity and have only $340 left at the end of the first year because of the high sales commission, whereas a 9 1/4 percent annuity, with no sales charge, might be worth $1,092.

A company with no sales charge might levy a 6 percent penalty on withdrawal; another might have no penalty after a few years.

The only way to compare annuities, Mintz says, is to tell the agent how much you expect to pay into the plan, and ask him to project, year by year, what you'd get in hard cash if you took the money out. You'll get two estimates -- one based on a guaranteed minimum interest rate, one based on today's high rates, which may or not be paid in the future.

Compare these results with the projected returns from your present annuity and see which yields the most. (Agents can easily provide these projectios. They're done by computer at the insurance company's headquarters.)

If you decide to switch, don't personally take your money out of the old annuity and reinvest in the new. If the funds pass through your hands they're considered current income, and a tax is due.

Instead, ask your old insurance company to issue the check directly to the new carrier, in a taxfree exchange. The insurance agent who handles the new plan can tell you how to do this.

For a model letter to an insurance company requesting a transfer, a worksheet on comparing the results of various annuities and a newsletter on the subject of the tax-free exchange (ask for Letter 11-79), send $2 to Joe Mintz, NROCA Press, P. O. Box 12066, Dallas, Tex. 75225.

Some people have losses on their annuities. For example, you may have deposited $5,000 over five years; but only have $4,000 to show for it, because of high sales commissions. In this case, Mintz says, you can withdraw the money personally, deduct the $1,000 loss from ordinary income, and reinvest the $4,000 in a better plan.

A special situation exists for teachers and employes of tax-exempt organizations who have money deducted from their pay each month for deposit into employer-approved annuities.

The best annuities may not be on the list for payroll deductions. In this case, you may continue to contribute to the approved plan, but strip part or all of the accumulated assets and transfer them, in a taxfree exchange, to a plan paying higher interest.

Some mutual-fund organizations welcome these transfers. In fact, they're offering a special type of tax-deferred annuity for teachers and employes of tax-exempt organizations. An advantage of mutual-fund groups is that you can switch your money from fund to fund, depending on the trend in interest rates and stock prices.

At the Fidelity Fund Group in Boston, for example, your annuity could currently be earning more than 13 percent in a money-market fund, and 10 1/2 to 12 percent in a bond fund. And you'd be free to switch part or all of your assets to a high-dividend-paying stock fund when the market turns up.