Retirement tax questions

On my 1099-R the amounts in boxes 1 and 2a are the same. Box 2b has an x. Box 7 has a 7 and an x in IRA/SEP/SIMPLE. I was 70 in May, 2012, so I started receiving amounts in Dec. 2012 or Jan. 2013. I receive $556.28 each month or $6675.36 a year.  Is this RDM? If yes, how do I determine how much the RDM is and how do I find the percent? I have used Turbo Tax Deluxe for probably 20 or more years, but this is the first time I remember having this trouble.