A group health plan shall provide that, to the extent that payment has been made under a State plan for medical assistance approved under title XIX of the Social Security Act [
42 U.S.C.
1396 et seq.] in any case in which a group health plan has a legal liability to make payment for items or services constituting such assistance, payment for benefits under the plan will be made in accordance with any State law which provides that the State has acquired the rights with respect to a participant to such payment for such items or services.