42 CFR § 405.425 - Effects of opting-out of Medicare.
(a) Except as provided in § 405.440, no payment may be made directly by Medicare or by any Medicare Advantage plan to the physician or practitioner or to any entity to which the physician or practitioner reassigns his right to receive payment for services.
(b) The physician or practitioner may not furnish any item or service that would otherwise be covered by Medicare (except for emergency or urgent care services) to any Medicare beneficiary except through a private contract that meets the requirements of this subpart.
(c) The physician or practitioner is not subject to the requirement to submit a claim for items or services furnished to a Medicare beneficiary, as specified in § 424.5(a)(6) of this chapter, except as provided in § 405.440.
(h) The death of a beneficiary who has entered into a private contract (or whose legal representative has done so) does not invoke § 424.62 or § 424.64 of this chapter with respect to the physician or practitioner with whom the beneficiary (or legal representative) has privately contracted.
(i) The physician or practitioner who has not been excluded under sections 1128, 1156 or 1892 of the Act and whose Medicare enrollment is not revoked under § 424.535 of this chapter may order, certify the need for, prescribe, or refer a beneficiary for Medicare-covered items, services, and drugs, provided the physician or practitioner is not paid, directly or indirectly, for such services (except as provided in § 405.440).
(j) The physician or practitioner who is excluded under sections 1128, 1156 or 1892 of the Act or whose Medicare enrollment is revoked under § 424.535 of this chapter may not order, prescribe or certify the need for Medicare-covered items, services, and drugs except, with respect to exclusions, as provided in § 1001.1901 of this title, and must otherwise comply with the terms of any exclusion in accordance with § 1001.1901 of this title effective with the date of the exclusion.