Bioengineered Skin Substitutes (also known as Cellular Tissue Products “CTPs”) have been placed on the list of approved RAC topics by CMS. Documentation for these products must support the service provided with the number of units billed as it correlates to the dosage increment specified in the HCPCS long descriptor. Units billed must also correspond to the actual quantity of skin substitute product applied to the wound during the treatment plan of the patient, including any appropriate discarded waste. The skin substitute product applied in the treatment of the patient must correlate with the appropriately rendered HCPCS code paid.