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Overview of Social Security Disability Programs: SSI and SSDI

There are two SSA disability programs: Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI). People often confuse them. Both programs are federally funded and administered by the Social Security Administration.

SSI and SSDI: A Comparison

The Social Security Administration has two disability programs which are federally funded. They are often confused because they have many similarities and some important differences. This article describes the differences between Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI).


  • Medical and functional disability criteria
    • Both programs have the same criteria for determining disability based on medical evidence and functional abilities.
  • Application process
    • Although there are different forms, both programs utilize the same application process and share one disability determination.
  • Health insurance
    • Each program has an associated health insurance program.

Key Difference: Non-Medical Criteria

  • SSI is based on need
  • SSDI is based on contributions by employees and employers to the Social Security trust fund as authorized by the Federal Insurance Contributions Act (FICA)

Other Differences

  • Benefit amount
  • Eligibility dates
  • Health insurance
  • Work incentives
Comparison of SSI and SSDI

Supplemental Security Income


Social Security Disability Insurance


Benefits to:

  • Low income
  • Disabled, blind, or elderly individuals

Benefits to:

  • Insured
  • Disabled or blind individuals and some eligible family members

Based on need:

  • Need is a complete picture of income, living arrangement, and personal resources
  • The monthly benefit amount is set each year by Congress; some states provide additional financial support

Based on earnings:

  • Employees & employers pay into Social Security
  • Benefit amount based on FICA contributions


  • Income
  • Living arrangement
  • Personal resources and assets


  • Recent wage information (e.g., W-2, paycheck stubs)
  • Work and earnings history

Date of eligibility:

  • Uses protective filing date (PFD)
  • PFD = Date applicant or case manager contacts SSA to indicate intent to file application

Date of eligibility:

  • Uses the “date of onset” (when the person became disabled), determined by DDS
  • Eligibility begins five months after date of onset

If an applicant has never worked, should they only apply for SSI?

In the SOAR model, case managers help individuals apply for both SSI and SSDI for every application. There may be circumstances in which an individual can be eligible based on someone else’s earnings record (e.g. parent or spouse), such as Disabled Adult Child (DAC) benefits. Always check with your local Social Security office representative for clarification on individual cases.

Disabled Adult Child (DAC)

An adult who becomes disabled before age 22 may be eligible for “child's” benefits if a parent is deceased or starts receiving retirement or disability benefits. Social Security considers this a child's benefit because it is paid on a parent's Social Security earnings record.
  • Applicants must meet the SSA disability criteria for adults and must be unmarried.
  • Since benefits are paid based on the parent's earnings record, it is not necessary for the adult child to have ever worked.
  • A disabled adult child already receiving SSI benefits should still check to see if benefits may be payable on a parent's earnings record. Circumstances may have changed (e.g. parent’s death, retirement or disability status) since the initial application. Higher benefits might be payable, and entitlement to Medicare may be possible.
  • SSDI DAC benefits continue as long as the individual remains disabled.