In December 2018, there were 9,919,094 people receiving Social Security disability benefits as disabled workers, disabled widow(er)s, or disabled adult children. The majority (86.1 percent) were disabled workers, 11.4 percent were disabled adult children, and 2.6 percent were disabled widow(er)s.

The number of disabled beneficiaries has risen from 1,812,786 in 1970 to 9,919,094 in 2018, driven predominately by an increase in the number of disabled workers. The number of disabled adult children has grown slightly, and the number of disabled widow(er)s has remained fairly level. In December 2018, there were 8,537,332 disabled workers; 1,127,181 disabled adult children; and 254,581 disabled widow(er)s receiving disability benefits.

Disabled beneficiaries aged 18–64 in current-payment status accounted for 4.5 percent of the population aged 18–64 in the United States. In five states, they represented less than 3 percent of the state population. The states with the highest rates of disabled beneficiaries—7 percent or more—were Alabama, Arkansas, Kentucky, Maine, Mississippi, and West Virginia.

The percentage of disabled-worker beneficiaries increases with age for both men and women. In December 2018, the largest percentage of disabled-worker beneficiaries was aged 60–64. Disability benefits convert to retirement benefits when the worker reaches full retirement age, 65–67, depending on the year of birth.

The average monthly benefit for disabled-worker beneficiaries is higher than that paid to disabled widow(er)s or disabled adult children. The reason for the difference is that disabled workers receive 100 percent of the primary insurance amount (PIA), compared with 71.5 percent for disabled widow(er)s and 50 percent for disabled adult children (if the worker is disabled or retired) or 75 percent (if the worker is deceased).

Because men have traditionally had higher earnings than women, their monthly benefit is higher. This is most obvious in the disabled-worker group. Benefits for disabled widow(er)s and disabled adult children are dependents' benefits, so their monthly benefit is a function of the worker's earnings. Therefore, a disabled widow's average benefit tends to be higher than that of a disabled widower because a male worker's earnings are higher than a female worker's. Benefit amounts are about the same for men and women in the disabled adult children group.

The impairment on which disability is based varies with the type of beneficiary. In December 2018, diseases of the musculoskeletal system and connective tissue were the primary reason disabled workers and disabled widow(er)s received benefits; intellectual disability was the predominant reason for disability among disabled adult children.