HISTORICAL NET PRICE.

(a) For purposes of determining the historical net price for a prescription drug, the allocation of price concessions is determined by the dollar value for non-product specific and product-specific rebates, discounts, chargebacks, fees, and other price concessions to the extent that the total amount of any such price concession is known to the health benefit plan issuer or administrator at the time of publication of the historical net price under Section 1662.103(a)(3)(D).

(b) To the extent that the total amount of any non-product specific and product-specific rebates, discounts, chargebacks, fees, or other price concessions is not known to a health benefit plan issuer or administrator at the time of publication of the historical net price under Section 1662.103(a)(3)(D), the issuer or administrator shall allocate those price concessions by using a good faith, reasonable estimate of the average price concessions based on the price concessions received over a period before the current reporting period and of equal duration to the current reporting period.