42 C.F.R. § 424.521 : Public Health — CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES — MEDICARE PROGRAM — CONDITIONS FOR MEDICARE PAYMENT — REQUIREMENTS FOR ESTABLISHING AND MAINTAINING MEDICARE BILLING PRIVILEGES — Request for payment by certain provider and supplier types

(a) Request for payment by certain provider and supplier types.
(1) The providers and suppliers identified in paragraph (a)(2) of this section may retrospectively bill for services when the provider or supplier has met all program requirements (including State licensure requirements), and services were provided at the enrolled practice location for up to-
(i) Thirty days prior to their effective date if circumstances precluded enrollment in advance of providing services to Medicare beneficiaries; or
(ii) Ninety days prior to their effective date if a Presidentially-declared disaster under the Robert T. Stafford Disaster Relief and Emergency Assistance Act, 42 U.S.C. 5121-5206 (Stafford Act) precluded enrollment in advance of providing services to Medicare beneficiaries.
(2) The provider and supplier types to which paragraph (a)(1) of this section applies are as follows:
(i) Physicians.
(ii) Non-physician practitioners.
(iii) Physician organizations.
(iv) Non-physician practitioner organizations.
(v) Ambulance suppliers.
(vi) Opioid treatment programs.
(vii) Part B hospital departments.
(viii) Clinical Laboratory Improvement Amendment labs.
(ix) Intensive cardiac rehabilitation facilities.
(x) Mammography centers.
(xi) Mass immunizers/pharmacies.
(xii) Radiation therapy centers.
(xiii) Home infusion therapy suppliers.
(xiv) Physical therapists.
(xv) Occupational therapists.
(xvi) Speech language pathologists.
(b) [Reserved]

42 C.F.R. §424.521

79 FR 72531, 12/5/2014; 84 FR 63203, 1/1/2020; 85 FR 70355, 1/1/2021; 86 FR 62240, 1/1/2022