(a) This part explains how disability determinations are made by the Railroad Retirement Board. In some determinations of disability entitlement, as described below, the Board makes the decision of disability under the Railroad Retirement Act based on the regulations set out in this part. However, in certain other determinations of disability entitlement (as also described below) the Board has the authority to decide whether the claimant is disabled as that term is defined in the Social Security Act and the regulations of the Social Security Administration.

(b) In order for a claimant to become entitled to a railroad retirement annuity based on disability for his or her regular railroad occupation, or to become entitled to a railroad retirement annuity based on disability for any regular employment as an employee, widow(er), or child, he or she must be disabled as those terms are defined in the Railroad Retirement Act. In order for a claimant to become entitled to a period of disability, to early Medicare coverage based on disability, to benefits under the social security overall minimum, or to a disability annuity as a surviving divorced spouse or remarried widow(er), the claimant must be found disabled as that term is defined in the Social Security Act.