MANY people joke about it, some even cry over it, but, in fact, the odds are improving that one day you will receive a windfall. Thirty states and the District of Columbia had lotteries in mid 1989, and the jackpots are huge. Most sudden money comes less spectacularly, from estates and court settlements; this year alone millions of Americans will inherit some wealth. If you are one of them, you face a nice problem: What do you do with your fresh fortune?

Unless you already have considerable money and know how to manage it, sudden wealth will require a new financial strategy. Your goal should be to preserve that hefty capital and make it work for you. Taking large risks with your riches is not only unnecessary but also unwise.

When that first check arrives, stash the cash for six months or so in a money market fund, a Treasury bill or some other short term investment. There it will remain, liquid and safe, while you sort out your options.

You may need a tax accountant right away. There is no income tax on inheritances or gifts, no matter how large, but there certainly is on lottery winnings and other prizes. Twenty percent of your lottery loot will be withheld for the U.S. Treasury, and you will almost surely owe more than that. Most million dollar lottery winnings come in 20 annual installments, which means you will have to pay quarterly estimated federal income taxes. Some states, though, do not tax their lottery winners unless they move to another state.

Dream a little. You have hit the jackpot for $5 million, which will come to you in $250,000 installments, before taxes, for the next 20 years. Your annual net windfall is $200,000. Welcome to the 28% flat tax bracket. Every penny of your adjusted gross income will be taxed at that rate. Immediately stash away $20,000 to cover taxes not being withheld.

So you have $180,000 to spend, save or invest. Enjoy part of it, but budget at least half for investments, and you will convert your 20 year windfall into a lifetime income. While there is no shelter from taxes on the winnings themselves, you surely can ease Uncle Sam’s bite on what they earn for you.

Start by building a portfolio of municipal bonds rated is higher. The interest you earn will be tax exempt. Also put a fixed amount each year in a flexible deferred annuity. You will postpone taxes on the earnings inside this remarkable retirement vehicle until you withdraw them. After you are 591/2, you can collect monthly lifetime income from your annuity, part of which will be untaxable. Or you can retrieve the entire cash value without penalty. just suppose your premiums are $40,000 a year and they earn 8%. If your tax rate remains 28%, you will net more than $11/2 million at the end of 20 years.

Or suppose your windfall is an inheritance that comes all at once. The main rule then is to diversify, so that you do not blow the whole wad on a single mistake. Consider a mix of a no load mutual fund that invests for growth and income; a single premium deferred annuity, in which you can invest as much as you want, all at one time; Treasury securities; and municipal bonds or unit trusts. Such trusts are sold by brokers, and they invest in a variety of municipal bonds. In mid 1989 they were yielding about 6.9% interest and you do not pay federal income taxes on that income.

Seek professional help. You probably will need an accountant for tax advice and a financial planner to devise a strategy for conserving your money and making it grow.

Many of the suddenly rich feel uneasy, not to say guilty, about their new wealth. Others make the mistake of quitting their jobs in euphoria, and some suffer by altering their life styles, changing too much about their lives too soon. A windfall can catapult you from one economic position to another, but attitudes, values and behavior change more slowly. So ease into your enviable new status gradually.