Thank you Steam Train for your thoroughness. The only form I have received with Fed Tax withholding was the 1099-SSA. It was entered on the correct location in TurboTax and populated the correct line on the e-file.
The request for info came by mail. Thanks for checking on the spam possibilities. They will not even provide information when I finally reached them by phone - only communication for what they wanted was by mail.
From your info, I can only guess that they wanted to confirm the amount. I'm just puzzled that they had not also got that info from Social Security.
