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Social Security Disability Insurance (SSDI): Program Description

By: World Institute on Disability

Social Security Disability Insurance (SSDI) is wage replacement income for those who pay FICA taxes when they have a disability meeting Social Security disability rules. SSDI provides a variety of benefits to family members when a primary wage earner in the family becomes disabled or dies. SSDI is financed with Social Security taxes paid by workers, employers, and self-employed persons. SSDI benefits are payable to disabled workers, widows, widowers, and children or adults disabled since childhood who are otherwise eligible.


In 1935, the federal government established a retirement benefits program for older workers in commerce and industry. Most employees are required by the Federal Insurance Contributions Act (FICA) to pay into the federal retirement fund through payroll deductions. FICA taxes are withheld from an individual’s salary to fund Social Security and Medicare programs. Self-employed individuals contribute to FICA through their federal tax returns.

In 1956, protection was established to cover "involuntary retirement" due to disability. Depending upon how long a person paid FICA taxes, an individual could access disability insurance.


To be eligible for the SSDI program, Social Security's definition of disability must be met. To meet medical eligibility requirements, an individual must be unable to engage in any Substantial Gainful Activity for at least 12 months. This is the same medical definition used in the Supplemental Security Income (SSI) program.

Social Security's Definition of Disability To be considered medically disabled according to Social Security rules, an individual must be unable to engage in any "Substantial Gainful Activity" (SGA) due to any medically determinable physical or mental impairment(s) which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months. In addition to being unable to perform his or her previous work, the person cannot, considering age, education, and work experience, engage in any other kind of SGA that exists in the national economy (1967 Amendments).

Substantial Gainful Activity (SGA) means any significant activity, physical or mental, which is performed for remuneration or profit over a reasonable period of time. To qualify, an individual’s monthly-earned income must be less than $830, the SGA amount for 2005. SGA dollar amounts are adjusted every January, a process called indexing.

Social Security has separate rules for those who are eligible for benefits because they are blind. SGA is $1,380 in 2005 for blind beneficiaries.

An individual may be able to support their disability claim and meet the above definition by:

Qualifying under the "Listing Level of Impairments" outlined in the SSA’s "Blue Book" or Qualifying under SSA’s sequential evaluation rules for determining disability. Social Security provides information to individuals applying for benefits called Qualify and Apply.

Social Security's complete definition of disability is also published on the web.

Individuals living with HIV/AIDS may also qualify under Social Security’s definition of disability by meeting the criteria for one of the 41 opportunistic infections listed in the Blue Book’s Adult Listing of Impairments (Immune Systems). A complete version of the Adult Listing of Impairments can be found on Social Security’s site in a PDF format. If an individual qualifies under one of the opportunistic infections, the Social Security Form called SSA 4814 can be used. This form is not currently available online, but can be obtained at a local Social Security office. HIV/AIDS service organizations should have these forms too.


SSDI requires a worker to pay FICA taxes for specified lengths of time, called credits. One SSDI credit is one quarter of the year (3 months); four SSDI credits are available in a year (12 months).

The number of work credits needed to qualify for SSDI depends on the age at disability onset. Generally, an individual will need 40 credits (10 years), 20 of which were earned in the last 10 years before they become disabled.

Before age 24: an individual may qualify if they have credits for 1-1/2 years of work (6 credits) within the past 3 years.

Ages 24 to 31: an individual may qualify if they have credit for 3 years of work (12 credits) out of the past 6 years.

Age 31 or older: In general, an individual needs to have the number of work credits shown in the table below. Unless an individual is blind, he or she must have earned at least 20 of the credits in the last 10 years before an individual became disabled.

Work Credits Required for SSDI Eligibility for those Born After 1929 Became Disabled At Age:

31 through 42 = 20
44 = 22
46 = 24
48 = 26
50 = 28
52 = 30
54 = 32
56 = 34
58 = 36
60 = 38
62 or older = 40

Individuals that are eligible for benefits include:

a wage earner in a family who becomes disabled according to Social Security’s rules and who has paid FICA taxes for the required length of time; worker's dependent widow or widower or; worker's Childhood Disability Beneficiary (CDB), formerly referred to as a Disabled Adult Child (DAC).


Individual must be a legal United States resident. SSA provides an explanation of the residency rules.

The People's Guide is another useful source of information for immigrants and Social Security.


The monthly disability benefit amount is based on the Social Security earnings record of the insured worker.

Eligibility for monthly SSDI benefits begins five months after Social Security determines the onset of disability.

Payments are made one month in arrears (behind payment date). For example, January’s payment due will be received in early February.

Benefits may continue as long as the individual continues to be disabled and otherwise meets work or other eligibility requirements. Benefits can stop for specific reasons, events, or activities.

A SSDI beneficiary will be periodically reviewed to determine if there has been any medical improvement in an individual's condition and to determine whether he or she continues to be eligible for benefits. These reviews are called a medical Continuing Disability Review (CDR) and work Continuing Disability Review (CDR).

When an individual reaches full retirement age, generally at age 65, he or she enrolls in the Social Security retirement program instead of SSDI.

An individual is eligible for retirement benefits depending on their year of birth. For example, individuals born before 1938 are eligible for retirement benefits at age 65.

Since January 2000, there is no limit on the amount you can earn while collecting Social Security retirement benefits. Before age retirement benefits, your disability benefits may be reduced depending on the amount you've earned.


A SSDI beneficiary may qualify for other public benefits, such as California State Disability Insurance or workers' compensation. SSDI benefits will be reduced if the combination of the SSDI benefit plus any workers' compensation payment and/or public disability payment exceeds 80% of what SSA considers average current earnings. SSA uses formulas to determine average current earnings. For example, SSA looks at earnings in the year prior to start of SSDI benefits.

For more information, see SSA's document: How Workers' Compensation And Other Disability Payments May Affect Your Benefits.


There is a full five month waiting period, after the onset date of the disability before benefits are paid to a beneficiary. A month is considered to be a part of the waiting period when the individual has not earned any income or their income is below Substantial Gainful Activity (SGA) ($830, as of 2005).

The individual is eligible for benefits starting in the sixth month.

Benefits are paid for the preceding month; in other words, they are paid one month in arrears. Thus, the SSDI beneficiary receives the first payment in the seventh month.


Processing the SSDI claim should take between 1-6 months if all required documentation is provided. If a claim is denied by Social Security an appeal is filed, the SSDI claim process can take longer.

Applicants may apply online or contact Social Security to schedule an appointment by phone or at the local office. Local Social Security offices can be found using SSA's office locator or by calling (voice) 800-772-1213 (TTY) 800-325-0778.

You will need to complete these forms:
SSA-3368 (Disability Report)
SSA-827 (Medical Releases)
SSA-3369 (Vocational Report)
Additional forms may be required. Check the local Social Security Office for details.

You may also need to supply the following documents:

Social Security number and proof of age such as certified copy of a birth certificate;
Names, addresses, and phone numbers of doctors, hospitals, clinics, and institutions where an individual received treatment, and the dates of treatment;
Names of all medications an individual is taking; An individual's medical records from doctors, therapists, hospitals, clinics, and caseworkers; Laboratory and test results;
A summary of an individual's work history and the kind of work performed;
An individual's most recent W-2 form, or tax return if self-employed;
Marriage and dependents information, and/or dates of any prior marriages and Proof of application to any other public benefit such as State Disability insurance programs or Workers' Compensation.


Although Social Security may determine that an individual became disabled prior to the application date for SSDI, retroactive payments covering the period before the application date cannot exceed 12 months.


Individuals should inform their medical providers that they are in the process of applying for benefits to insure that medical providers will recognize the need to clearly document medical findings that will support disability claims. This is so that they can be prepared to submit medical records when requested by Social Security.