42 USC 425 - Additional rules relating to benefits based on disability

(a) Suspension of benefits 
If the Commissioner of Social Security, on the basis of information obtained by or submitted to the Commissioner, believes that an individual entitled to benefits under section 423 of this title, or that a child who has attained the age of eighteen and is entitled to benefits under section 402 (d) of this title, or that a widow or surviving divorced wife who has not attained age 60 and is entitled to benefits under section 402 (e) of this title, or that a widower or surviving divorced husband who has not attained age 60 and is entitled to benefits under section 402 (f) of this title, may have ceased to be under a disability, the Commissioner of Social Security may suspend the payment of benefits under such section 402 (d), 402 (e), 402 (f), or 423 of this title until it is determined (as provided in section 421 of this title) whether or not such individuals disability has ceased or until the Commissioner of Social Security believes that such disability has not ceased. In the case of any individual whose disability is subject to determination under an agreement with a State under section 421 (b) of this title, the Commissioner of Social Security shall promptly notify the appropriate State of the Commissioners action under this subsection and shall request a prompt determination of whether such individuals disability has ceased. For purposes of this subsection, the term disability has the meaning assigned to such term in section 423 (d) of this title. Whenever the benefits of an individual entitled to a disability insurance benefit are suspended for any month, the benefits of any individual entitled thereto under subsection (b), (c), or (d) of section 402 of this title, on the basis of the wages and self-employment income of such individual, shall be suspended for such month. The first sentence of this subsection shall not apply to any child entitled to benefits under section 402 (d) of this title, if he has attained the age of 18 but has not attained the age of 22, for any month during which he is a full-time student (as defined and determined under section 402 (d) of this title).
(b) Continued payments during rehabilitation program 
Notwithstanding any other provision of this subchapter, payment to an individual of benefits based on disability (as described in the first sentence of subsection (a) of this section) shall not be terminated or suspended because the physical or mental impairment, on which the individuals entitlement to such benefits is based, has or may have ceased, if
(1) such individual is participating in a program consisting of the Ticket to Work and Self-Sufficiency Program under section 1320b–19 of this title or another program of vocational rehabilitation services, employment services, or other support services approved by the Commissioner of Social Security, and
(2) the Commissioner of Social Security determines that the completion of such program, or its continuation for a specified period of time, will increase the likelihood that such individual may (following his participation in such program) be permanently removed from the disability benefit rolls.