You must take at least a required minimum distribution (RMD) from your IRA after you reach age 70 1/2. If not, you face a 50 percent penalty. Typically, your RMD begins at nearly 4 percent of your IRA balance, according to IRS tables.

Say you have just over $300,000 in your IRA. In your early 70s, your RMD would be around $12,000. You can take more, but not less.

If you take out $5,000, for instance, you’d be $7,000 short of your RMD. You’d owe a 50 percent penalty: $3,500.

The official required beginning date, or RBD, for IRA required distributions is April 1 of the year after the year you reach age 70 1/2. If you were born in the second half of 1941, for example, your RBD is April 1, 2013.

By then, you must start with an RMD that’s based on your year-end balance from 2011, and follow up with another RMD by December 31, 2013, based on your year-end balance from 2012. Taking two RMDs in one year could push you into a higher tax bracket so you might be better off starting early, and taking one RMD in 2012. The same strategy applies to everyone: think of taking your first RMD in the year you reach age 70 1/2.