CPT codes 21076-21085 is impression and custom prep of prosthesis. When do you bill the code out? On the day the doctor fabricates the prosthesis or the date of delivery of the prosthesis?June 26, 2012 by Admin « Back to Previous Page Answer Question ▲0 ▼ ♥ 0 Marked as spamAsked on June 26, 20121411 viewsFollowUnfollow ▲1 ▼✔ Private answerAccording to most carriers it should be billed out on the delivery date.Marked as spamAnswered on June 27, 2012 « Back to Previous Page Post your AnswerAttach YouTube/Vimeo clip putting the URL in brackets: [https://youtu.be/Zkdf3kaso] Notify me of follow