49 C.F.R. § 390.401 – Applicability.

(a) General. Beginning on January 1, 2021, and except as provided in paragraphs (b)(1) and (2) of this section, this subpart applies to the following actions, irrespective of duration, or the presence or absence of compensation, by motor carriers operating commercial motor vehicles to transport passengers:
1. (1) The lease of passenger-carrying commercial motor vehicles; and
2. (2) The interchange of passenger-carrying commercial motor vehicles between motor carriers.
(b) Exceptions—(1) Contracts and agreements between motor carriers of passengers with active passenger carrier operating authority registrations. This subpart does not apply to contracts and agreements between motor carriers of passengers that have active passenger carrier operating authority registrations with the Federal Motor Carrier Safety Administration when one such motor carrier acquires transportation service(s) from another such motor carrier(s).
(2) Financial leases. This subpart does not apply to a contract (however designated, e.g., lease, closed-end lease, hire purchase, lease purchase, purchase agreement, installment plan, demonstration or loaner vehicle, etc.) between a motor carrier and a bank or similar financial organization or a manufacturer or dealer of passenger-carrying commercial motor vehicles allowing the motor carrier to use the passenger-carrying commercial motor vehicle.
(c) Penalties. If the use of a passenger-carrying commercial motor vehicle is conferred on one motor carrier subject to this subpart by another such motor carrier without a lease or interchange agreement, or pursuant to a lease or interchange agreement that fails to meet all applicable requirements of subpart G, both motor carriers shall be subject to a civil penalty.