; (iii) whose entitlement to a benefit described in subparagraph (A) of such section has terminated due to performance of substantial gainful activity; and (iv) who is retired under chapter 61 of this title. (C) The Secretary of Defense shall coordinate with the Secretary of Health and Human Services and the Commissioner of Social Security to notify persons described in subparagraph (B) of, and provide information and counseling regarding, the effects of not enrolling in the supplementary medical insurance program under part B of title XVIII of the Social Security Act ( 42 U.S.C. 1395j et seq.), as described in subparagraph (A). . (2) Conforming amendment Paragraph (2)(A) of such subsection is amended by striking is enrolled and inserting except as provided by paragraph (6), is enrolled . (3) Identification of persons Section 1110a of such title is amended by adding at the end the following new subsection: (c) Certain individuals not required to enroll in Medicare Part B In carrying out subsection (a), the Secretary of Defense shall coordinate with the Secretary of Health and Human Services and the Commissioner of Social Security to— (1) identify persons described in subparagraph (B) of section 1086(d)(6) of this title