The definition and discussion of disability for any regular employment are found in §§ 220.26 through 220.184.

An employee, widow(er), or child is disabled for any regular employment if he or she is unable to do any substantial gainful activity because of a medically determinable physical or mental impairment which meets the duration requirement defined in § 220.28. In the case of a widow(er), the permanent physical or mental impairment must have prevented work in any regular employment before the end of a specific period (see § 220.30). In the case of a child, the permanent physical or mental impairment must have prevented work in any regular employment since before age 22. To meet this definition of disability, a claimant must have a severe impairment, which makes him or her unable to do any previous work or other substantial gainful activity which exists in the national economy. To determine whether a claimant is able to do any other work, the Board considers a claimant's residual functional capacity, age, education and work experience. See § 220.100 for the process by which the Board evaluates disability for any regular employment. This process applies to employees, widow(er)s, or children who apply for annuities based on disability for any regular employment. This process does not apply to surviving divorced spouses or remarried widow(er)s who apply for annuities based on disability.

A physical or mental impairment must result from anatomical, physiological, or psychological abnormalities which can be shown by medically acceptable clinical and laboratory diagnostic techniques. A physical or mental impairment must be established by medical evidence consisting of signs, symptoms, and laboratory findings, not only by the claimant's statement of symptoms. (See § 220.113 for further information about what is meant by symptoms, signs, and laboratory findings.) (See also § 220.112 for the effect of a medical opinion about whether or not a claimant is disabled.)

Unless the claimant's impairment is expected to result in death, it must have lasted or must be expected to last for a continuous period of at least 12 months. This is known as the duration requirement.

Work is considered to be substantial gainful activity if it—

(a) Involves doing significant and productive physical or mental duties; and

(b) Is done or is intended to be done for pay or profit. (See § 220.141 for a detailed explanation of what is substantial gainful activity.)

In order to be found disabled for any regular employment, a widow(er) must have a permanent physical or mental impairment which prevented work in any regular employment since before the end of a specific period as defined in part 216 of this chapter.