42 CFR §447.507

1. (a)Identification of a 5i drug. A manufacturer must identify to CMS each covered outpatient drug that qualifies as a 5i drug.
2. (b)Not generally dispensed through a retail community pharmacy. A manufacturer must determine if the 5i drug is not generally dispensed through a retail community pharmacy based on the percentage of sales to entities other than retail community pharmacies.
   1. (1)A 5i drug is not generally dispensed through a retail community pharmacy if 70 percent or more of the sales (based on units at the NDC-9 level) of the 5i drug, were to entities other than retail community pharmacies or wholesalers for drugs distributed to retail community pharmacies.
   2. (2)A manufacturer is responsible for determining and reporting to CMS whether a 5i drug is not generally dispensed through a retail community pharmacy on a monthly basis.