The Medicare Modernization Act section 303(e)(1) added section 1842(o)(5)(C) of the Social Security Act which requires that, beginning January 1, 2005, a furnishing fee will be paid for items and services associated with clotting factor. 

The Center for Medicare and Medicaid Services (CMS) includes the clotting factor furnishing fee in the published national payment limits for clotting factor billing codes. When the national payment limit for a clotting factor is not included on the Average Sales Price (ASP) Medicare Part B Drug Pricing File or the Not Otherwise Classified (NOC) Pricing File, the contractor must make payment for the clotting factor as well as make payment for the furnishing fee

CMS guidance requires physicians and other providers to bill using the appropriate HCPCS or CPT code and to accurately report the units of service. Physicians and other providers should ensure that the units billed do not exceed the maximum number of units per day based on the code descriptor, reporting instructions associated with the code, and/or other CMS local or national policy.