The SSA administers two different programs that provide benefits to those who are unable to work due to disability. These programs have very different requirements, and it is possible for applicants to receive both types of benefits if they qualify.
SSDI benefits are not paid until an applicant has been disabled for six full months. Conversely, Supplemental Security Income (SSI) benefits can be paid for the first full month after a claim is filed or an applicant becomes eligible.