and supplies (including labor, storage, transportation, maintenance, and similar costs), the cost of complying with Federal and State regulations specific to the delivery and transportation of liquid oxygen, and any other cost factors the Secretary deems appropriate after consulting with stakeholders such as suppliers, providers, patients and patient advocates, and manufacturers. (iii) Monthly add-on for high-flow patients (I) In general Subject to subclause (II), the Secretary shall establish a non-budget neutral add-on to the payment amount under clause (i) when the prescribing practitioner orders an oxygen flow rate equal to or greater than 6 liters per minute. (II) Add-on amount The add-on amount shall equal the per pound cost of the oxygen exceeding the amount required to provide a liter flow that is equal to or greater than 6 liters per minute. (iv) Periodic assessment of the base rate The Secretary shall assess at least once every 3 years the adequacy of the payment amounts under this subparagraph on a cost-related basis or other economical and equitable basis. (v) Transitional interim payment (I) In general For items and services furnished on or after the date of the enactment of the SOAR Act of 2024 and prior to the implementation of the payment amount established under this subparagraph, the Secretary shall adopt a transitional interim payment amount for liquid oxygen, and liquid oxygen equipment, supplies, and services in an amount equal to 200 percent of the 2015 Durable Medical Equipment, Prosthetics/Orthotics & Supplies Fee Schedule updated by the consumer price index for all urban consumers (United States city average) for years 2016 through 2024. (II) Update This amount shall be updated annually by the projected percentage change in the consumer price index for all urban consumers (United States city average) for the 12-month period ending on December 31 of the previous year, until the Secretary implements the payment amount under this subparagraph. (vi) Coverage criteria (I) In general Not later