(a) The provisions of parts 831, 835, 837 through 839, 841 through 847, 870, 890, and 891 of this chapter remain in effect, as applicable, except to the extent that they are inconsistent with one or more provisions of this part or implementing directives prescribed by the Director under § 850.104.

(b) The provisions of this part do not supersede or alter any functions performed by a private insurance company or carrier with which OPM has entered into a contract, or with which OPM may enter into a contract in the future, under chapter 87 or 89 of title 5, United States Code, or under any other provision of law or regulation.