(4)
A recipient of benefits based on disability under this subchapter may be determined not to be entitled to such benefits on the basis of a finding that the physical or mental impairment on the basis of which such benefits are provided has ceased, does not exist, or is not disabling only if such finding is supported by—
(A)
in the case of an individual who is age 18 or older—
(i)
substantial evidence which demonstrates that—
(I)
there has been any medical improvement in the individual’s impairment or combination of impairments (other than medical improvement which is not related to the individual’s ability to work), and
(II)
the individual is now able to engage in substantial gainful activity; or
(ii)
substantial evidence (except in the case of an individual eligible to receive benefits under section
1382h of this title) which—
(I)
consists of new medical evidence and a new assessment of the individual’s residual functional capacity, and demonstrates that—
(aa)
although the individual has not improved medically, he or she is nonetheless a beneficiary of advances in medical or vocational therapy or technology (related to the individual’s ability to work), and
(bb)
the individual is now able to engage in substantial gainful activity, or
(II)
demonstrates that—
(aa)
although the individual has not improved medically, he or she has undergone vocational therapy (related to the individual’s ability to work), and
(bb)
the individual is now able to engage in substantial gainful activity; or
(iii)
substantial evidence which demonstrates that, as determined on the basis of new or improved diagnostic techniques or evaluations, the individual’s impairment or combination of impairments is not as disabling as it was considered to be at the time of the most recent prior decision that he or she was under a disability or continued to be under a disability, and that therefore the individual is able to engage in substantial gainful activity; or
(B)
in the case of an individual who is under the age of 18—
(i)
substantial evidence which demonstrates that there has been medical improvement in the individual’s impairment or combination of impairments, and that such impairment or combination of impairments no longer results in marked and severe functional limitations; or
(ii)
substantial evidence which demonstrates that, as determined on the basis of new or improved diagnostic techniques or evaluations, the individual’s impairment or combination of impairments, is not as disabling as it was considered to be at the time of the most recent prior decision that the individual was under a disability or continued to be under a disability, and such impairment or combination of impairments does not result in marked and severe functional limitations; or
(C)
in the case of any individual, substantial evidence (which may be evidence on the record at the time any prior determination of the entitlement to benefits based on disability was made, or newly obtained evidence which relates to that determination) which demonstrates that a prior determination was in error.
Nothing in this paragraph shall be construed to require a determination that an individual receiving benefits based on disability under this subchapter is entitled to such benefits if the prior determination was fraudulently obtained or if the individual is engaged in substantial gainful activity, cannot be located, or fails, without good cause, to cooperate in a review of his or her entitlement or to follow prescribed treatment which would be expected
(i)
to restore his or her ability to engage in substantial gainful activity, or
(ii)
in the case of an individual under the age of 18, to eliminate or improve the individual’s impairment or combination of impairments so that it no longer results in marked and severe functional limitations. Any determination under this paragraph shall be made on the basis of all the evidence available in the individual’s case file, including new evidence concerning the individual’s prior or current condition which is presented by the individual or secured by the Commissioner of Social Security. Any determination made under this paragraph shall be made on the basis of the weight of the evidence and on a neutral basis with regard to the individual’s condition, without any initial inference as to the presence or absence of disability being drawn from the fact that the individual has previously been determined to be disabled.