((a)) The Secretary is authorized to provide medical care, in accordance with the provisions of subsection (b) of this section, for—

((1)) the spouse or child of a veteran who has a total disability, permanent in nature, resulting from a service-connected disability,

((2)) the surviving spouse or child of a veteran who (A) died as a result of a service-connected disability, or (B) at the time of death had a total disability permanent in nature, resulting from a service-connected disability,

((3)) the surviving spouse or child of a person who died in the active military, naval, air, or space service in the line of duty and not due to such person’s own misconduct, and

((4)) an individual designated as a primary provider of personal care services under who is not entitled to care or services under a health-plan contract (as defined in ),

((b)) In order to accomplish the purposes of subsection (a) of this section, the Secretary shall provide for medical care in the same or similar manner and subject to the same or similar limitations as medical care is furnished to certain dependents and survivors of active duty and retired members of the Armed Forces under chapter 55 of title 10 (CHAMPUS), by—

((1)) entering into an agreement with the Secretary of Defense under which that Secretary shall include coverage for such medical care under the contract, or contracts, that Secretary enters into to carry out such chapter 55, and under which the Secretary of Veterans Affairs shall fully reimburse the Secretary of Defense for all costs and expenditures made for the purposes of affording the medical care authorized pursuant to this section; or

((2)) contracting in accordance with such regulations as the Secretary shall prescribe for such insurance, medical service, or health plans as the Secretary deems appropriate.

((c)) For the purposes of this section, a child between the ages of eighteen and twenty-three (1) who is eligible for benefits under subsection (a) of this section, (2) who is pursuing a full-time course of instruction at an educational institution approved under chapter 36 of this title, and (3) who, while pursuing such course of instruction, incurs a disabling illness or injury (including a disabling illness or injury incurred between terms, semesters, or quarters or during a vacation or holiday period) which is not the result of such child’s own willful misconduct and which results in such child’s inability to continue or resume such child’s chosen program of education at an approved educational institution shall remain eligible for benefits under this section until the end of the six-month period beginning on the date the disability is removed, the end of the two-year period beginning on the date of the onset of the disability, or the twenty-third birthday of the child, whichever occurs first.

((d))

((1))

((A)) An individual otherwise eligible for medical care under this section who is also entitled to hospital insurance benefits under part A of the medicare program is eligible for medical care under this section only if the individual is also enrolled in the supplementary medical insurance program under part B of the medicare program.

((B)) The limitation in subparagraph (A) does not apply to an individual who—

((i)) has attained 65 years of age as of ; and

((ii)) is not enrolled in the supplementary medical insurance program under part B of the medicare program as of that date.

((2)) Subject to paragraph (3), if an individual described in paragraph (1) receives medical care for which payment may be made under both this section and the medicare program, the amount payable for such medical care under this section shall be the amount by which (A) the costs for such medical care exceed (B) the sum of—

((i)) the amount payable for such medical care under the medicare program; and

((ii)) the total amount paid or payable for such medical care by third party payers other than the medicare program.

((3)) The amount payable under this subsection for medical care may not exceed the total amount that would be paid under subsection (b) if payment for such medical care were made solely under subsection (b).

((4)) In this subsection:

((A)) The term “medicare program” means the program of health insurance administered by the Secretary of Health and Human Services under title XVIII of the Social Security Act ( et seq.).

((B)) The term “third party” has the meaning given that term in .

((e)) Payment by the Secretary under this section on behalf of a covered beneficiary for medical care shall constitute payment in full and extinguish any liability on the part of the beneficiary for that care.