Form SSA-2458, Report of Confidential Social Security Benefit Information, has information about a person's Retirement Survivors Disability Insurance or Supplemental Security Income benefits. It is typically sent upon request to the person receiving the benefit, but a third party can also request it from the Social Security Administration.
Taxpayers need to send Form SSA-2458 to any office that requires verification of either RSDI or SSI benefits. As of 2016, the form is not available for download on the Social Security Administration website. People who need a copy of any form not listed on the website may request it from their local office or by calling 800-772-1213.