20 CFR §416.999a

1. (a)You can have your eligibility to benefits reinstated under expedited reinstatement if—
   1. (1)You were previously eligible for a benefit based on disability or blindness as explained in § 416.202;
   2. (2)Your disability or blindness eligibility referred to in paragraph (a)(1) of this section was terminated because of earned income or a combination of earned and unearned income;
   3. (3)You file your request for reinstatement timely under § 416.999b; and
   4. (4)In the month you file your request for reinstatement—
      1. (i)You are not able or become unable to do substantial gainful activity because of your medical condition as determined under paragraph (c) of this section.
      2. (ii)Your current impairment is the same as or related to the impairment that we used as the basis for your previous eligibility referred to in paragraph (a)(2) of this section,
      3. (iii)You are disabled or blind, as determined under the medical improvement review standard in §§ 416.994 or 416.994a, and
      4. (iv)You meet the non-medical requirements for eligibility as explained in § 416.202.
2. (b)You are eligible for reinstatement if you are the spouse of an individual who can be reinstated under § 416.999a if—
   1. (1)You were previously an eligible spouse of the individual;
   2. (2)You meet the requirements for eligibility as explained in § 416.202 except the requirement that you must file an application; and
   3. (3)You request reinstatement.
3. (c)We will determine that you are not able to do substantial gainful activity because of your medical condition, under paragraph (a)(4)(i) of this section, when:
   1. (1)You certify under § 416.999b(e) that you are unable to do substantial gainful activity because of your medical condition;
   2. (2)You are not able or become unable to do substantial gainful activity in the month you file your request for reinstatement; and
   3. (3)We determine that you are disabled under paragraph (a)(4)(iii) of this section.