If you are still having trouble with GET MY PAYMENT then try this:
1. Put dashes in your Social Security Number ( ex: 123-45-6789)
2. Go to the following US Postal Service site and enter just your address without the zip code then select Find:
This will give you the address on file for you with the USPS. Copy and paste that information to include the 9-digit Zip Code into GET MY PAYMENT. Hopefully this will help those of you that are still having trouble with Get My Payment. It worked for me.