(a) If you are an adult:

(1) A disabling impairment is an impairment (or combination of impairments) which, of itself, is so severe that it meets or equals a set of criteria in the Listing of Impairments in appendix 1 of subpart P of part 404 of this chapter or which, when considered with your age, education and work experience, would result in a finding that you are disabled under § 416.994, unless the disability redetermination rules in § 416.987(b) apply to you.

(2) If the disability redetermination rules in § 416.987 apply to you, a disabling impairment is an impairment or combination of impairments that meets the requirements in §§ 416.920 (c) through (f).

(b) If you are a child, a disabling impairment is an impairment (or combination of impairments) that causes marked and severe functional limitations. This means that the impairment or combination of impairments:

(1) Must meet, medically equal, or functionally equal the listings, or

(2) Would result in a finding that you are disabled under § 416.994a.

(c) In determining whether you have a disabling impairment, earnings are not considered.