If we are talking about Social Security, and the "proof of award letter," then I would recommend this link. In order to print it off online, you need to create an account at the Social Security site, here's the link.
If you do not want to create an online account, you can also call them at:
1-800-772-1213 (TTY 1-800-325-0778), Monday through Friday from 7 a.m. to 7 p.m.
I hope that helps.