The oldest of America’s 75 million baby boomers are turning 70 this year. That means the IRS will soon be requiring them to start cashing out their tax-deferred retirement savings accounts. How you handle these withdrawals can have a profound effect on your own retirement and on what you leave to your heirs.

As a general rule, if you don’t need the money in these accounts to live on, it can be wise to keep as much as possible in them, rather than withdrawing it. This can reduce your income taxes, plus there can be significant tax advantages in leaving money to your heirs in a tax-sheltered account rather than giving it to them outright.

Here’s a look at the rules: Once you turn age 70½, the IRS requires you to take “required minimum distributions,” or RMDs, from your IRA and 401(k) accounts. You’ll also have to pay income tax on these withdrawals.

If you don’t take these distributions, you can be hit with a 50% penalty on whatever amount you were required to withdraw but didn’t.

The exact amount that must be withdrawn is based on an IRS worksheet. The worksheets are available on the IRS website. (There’s one for most people, and a separate one if your spouse is your sole beneficiary and is more than 10 years younger than you are.)

Generally, your first required distribution will be a fairly small percentage of the assets in your account, but the percentage increases each year after that.

Not everyone with a retirement account has to take RMDs, however. For instance:

• Roth IRAs don’t require you to take minimum distributions – although if you leave the account to an heir, your heir might have to start taking them fairly quickly after you pass away.
• If you’re still working, and if your company’s retirement plan allows it, you can often wait until April 1 of the year after you retire to start receiving distributions. (This is not true for SEP or SIMPLE plans, though, and it’s also not true if you own at least five percent of the company.)
• If you’ve invested in a “qualifying longevity annuity contract,” you may be able to shelter up to $125,000 of your investment and not have to take distributions until age 85.

Typically, you must take any RMDs by December 31 of each year. However, you’re allowed to wait to take your first year’s RMD until April 1 of the year following the year in which you turn 70½. So if you turn 70½ in January 2017, you can wait until April 1, 2018 to take your first distribution.

This might or might not be a good idea. For instance, if you wait, you might have to take two distributions in one calendar year. This could push you into a higher tax bracket for the year, and could also affect how much tax is due on your Social Security benefits.

If you want to avoid or minimize your required distributions, there are some strategies you can consider.

For instance, you can convert some of your regular IRA funds into a Roth IRA. The downside to this is that you’ll have to pay income tax on the amount you convert, but there will be no more RMDs, you’ll pay no tax on any amounts you decide to withdraw in the future, and if your heirs inherit the IRA, they’ll also pay no tax on their withdrawals.

The ideal time to make such a conversion is usually after you retire, when you’ll presumably be in a lower tax bracket.

If you’re charitably minded, another technique is to make a charitable contribution directly from your IRA. You can contribute up to $100,000 a year from an IRA, and any amount you contribute reduces the amount of your RMD for that year.

You won’t get a charitable deduction for the contribution, but you’ll reduce your adjusted gross income, which can have many other tax advantages. And giving to a charity from an IRA is far better than giving assets from a taxable account if you can’t take a charitable deduction (for instance, because you don’t itemize deductions).

What if you’re over 70½ and you didn’t realize you were supposed to take RMDs? You might be able to avoid the 50% penalty by filing Form 5329 with the IRS and attaching an explanation of how you were confused about the law.

In general, navigating RMDs and getting the best tax results for you and your family can be very tricky, and if you’re approaching age 70 or older, it can be good to talk to an elder law attorney about how best to handle the issue.