An adult who became disabled before the age of 22 may be eligible for “child’s” benefits if a parent is deceased or starts receiving retirement or disability benefits. This is considered a "child's" benefit because it is paid on the parent's Social Security earnings record.
The "adult child"—including an adopted child, or, in some cases, a step-child, grandchild, or step-grandchild—must be unmarried, age 18 or older, and have a disability that started before age 22.