A person qualifies for SSDI if:
they have a physical or mental condition that prevents them from engaging in any “substantial gainful activity” (“SGA”), and
the condition is expected to last at least 12 months or result in death, and

they are under the age of 65, and

generally, they have accumulated 20 social security credits in the last 10 years prior to the onset of disability (normally four credits per full or partial year); one additional credit is required for every year by which the worker’s age exceeds 42.

The work requirement is waived for applicants who can prove that they became disabled at or before the age of 22, as these individuals may be allowed to collect on their parent’s or parents’ work credits. The parent(s) experience no loss of benefits.

Medical evidence is signs, symptoms and laboratory findings and is required to document the claim. Symptoms, such as pain, are considered but must be reasonably expected to come from a medically determinable impairment which the claimant is diagnosed to have. the claim.

Medical evidence that demonstrates the applicant’s inability to work is required. SSA may require the applicant to visit a third-party physician for medical documentation, often to supplement the evidence treating sources do not supply. The applicant may meet a SSA medical listing for their condition. If their condition does not meet the requirements of a listing, their residual functional capacity is considered, along with their age, past relevant work, and education, in determining their ability to perform either their past work, or other work generally available in the national economy.
Residual functional capacity (RFC) is classified according to the five exertional levels of work defined in the Dictionary of Occupational Titles which are: Sedentary, Light, Medium, Heavy, and Very Heavy. If the residual functional capacity of an individual equals the previous work performed, the claim is denied on the basis that the individual can return to former work. If the residual functional capacity is less than former work then the RFC is applied against a vocational grid that considers the individual’s age, education and transferability of formerly learned and used skills. The vocational grid directs an allowance or denial of benefits.

Applicants may hire a lawyer to help them apply or appeal.
The fee that a representative can charge for SSDI representation is set by law. Currently, under the SSA’s fee agreement approval process, it is 25 percent of the retroactive dollar amount awarded, not to exceed $6,000. Some representatives may charge fees for costs related to the claim, such as photocopy and medical record collection expenses.

Generally, the person qualifying for benefits is determined to be capable of managing their own financial affairs, and the benefits are disbursed directly to them. In the case of persons who have a diagnosed mental impairment which interferes with their ability to manage their own finances, the Social Security Administration may require that the person assign someone to be their representative payee. This person will receive the benefits on behalf of the disabled individual, and disburse them directly to payers such as landlords, or to the disabled person, while providing money management assistance (help with purchasing items, limiting spending money, etc.). The representative payee often does not charge a fee for this service, especially if it’s a friend or relative. Social service agencies who are assigned as payee are NOT prohibited from charging a fee, although the maximum fee is set by Social Security. The fee is the same for ALL recipients, except it can be larger for those with severe substance abuse problems (Social Security determines when a higher fee can be charged, not the representative payee.) Some states and counties have representative payee agencies (also called substitute payee programs) which receive the benefits on behalf of the disabled person’s social worker, and disburse the benefits per the social worker’s instructions. A payee can be very helpful in the instance of homeless individuals who need assistance paying down debts (like utility bills) and saving for housing.