Q. I think that RMDs are calculated using the account balances as of the “end of last year.” What I am not clear on is whether the person’s age used is as of the end of last year or the end of this year, and whether the rules are different for a traditional IRA at a brokerage firm versus the TSP.
IRS Pub 590 page 36 says: “To figure the required minimum distribution for 2014, divide your account balance at the end of 2013 by the distribution period from the table. This is the distribution period listed next to your age (as of your birthday in 2014) in Table III in Appendix C, unless the sole beneficiary of your IRA is your spouse who is more than 10 years younger than you.”
So this seems to mean your age at the end of this year.
A. The IRS Pub 590 rules apply, and you are reading them correctly. Use the trailing account balance and your age at the end of the distribution year.