@abctax55 The first time it happened we turned it into a Congressional, which solved the problem.  But she has outlived Senator McCain.  It was more urgent then, because a refund was involved.  This time it's not our problem that they want to freeze the account.  I have replied to the current letter with copies of the two earlier notices and her Social Security card, and put the ball back in their court at least for now. 

@qbteachmt Are your mother's Social Security benefits now based on her late husband's earnings record?  I think that's where the glitch is, when they refigure the payments to widows.  The SSA-1099 will have the SSN of the deceased spouse somewhere on it, followed by a "D", and that is considered part of the survivor's account number.  I should be keeping copies of these, but I haven't.