26 CFR §51.6302-1

1. (a)Fee to be paid by electronic funds transfer. Under the authority of section 6302(a), the fee imposed on branded prescription drug sales by section 9008 and § 51.5 must be paid by electronic funds transfer as defined in § 31.6302-1(h)(4)(i) of this title, as if the fee were a depository tax. For the time for paying the fee, see § 51.8.
2. (b)Effective/applicability date. This section applies on and after July 28, 2014.