Enter interest from the IRS like a 1099Int and put the amount in box 1. Enter it manually and just enter IRS for the payer. Don't enter any other info like the address or a EIN.
Enter a 1099-Int under
Federal on left
Wages & Income at top
Interest and Dividends
Interest on 1099INT - Click the Start or Revisit button
Don't enter a bank or broker name and don't try to import it. At the bottom pick - Change How I enter my Form
Then on the next screen pick I'll Type it in Myself
