Was the 401K also at Vanguard? Is the 1099R from the 401K or the IRA? You probably had to take the RMD from the 401K before rolling over to the IRA. Or is the 1099R for the rollover? Then it's from the 401K.
Leave the 1099R the way it is. Do not put an X in the little IRA box. @dmertz
