Seventeen years before the Americans with Disabilities Act (ADA), President Richard Nixon, of all people, signed into law the Rehabilitation Act of 1973.
This act was something of a precursor to the ADA but had requirements limited to federal agencies and those who were receiving federal funding. The ADA broadened the expectations to cover essentially all businesses. Where they are similar is the basic principle in ensuring that there is no discrimination against those with disabilities.
Other sections of the law cover hiring practices and the prevention of discrimination in the workplace but Section 504, posters of which you should be able to see in your local SSA office, mandates that ‘no otherwise qualified individual with a disability is, solely because of disability, excluded from participation in, denied the benefits of, or subjected to discrimination under the programs and activities they conduct’. This means that SSA have to accommodate the needs of any member of the public with a disability when they are in contact with them. If you have a disability and need an accommodation you do have to ask for it- they aren’t expected to just know or assume what you may need. You can request the accommodation at your local office or at the national number (1-800-772-1213).
If you feel your needs were not met you can file a complaint using this form: Complaint Form for allegations of program discrimination by the social security administration (ssa.gov)
SSA have a whole webpage dedicated to Section 504 which you can read all about here 504 Overview | Accessibility | Social Security Administration (ssa.gov)