The Coding Sleuth 10
by Tara Conklin
We come seeking the truth. What truths will we find?
This week our investigation takes us into another part of the same neighborhood we ventured into last week. However this time our culprits have tried to confound us with the proper coding of skin grafts and preparation of the donor site.
We took our team deep into codes 15000-15401 and found the verbiage in one set of codes did not repeat itself in another set of codes making the appropriate coding hard to accomplish. This was the case of “The Goose and The Gander”.
The first thing we did was read through the section guidelines in order to obtain a basic knowledge of the coding application of grafts. Immediately we find the correct identification of the codes is based on the “recipient site” not where the graft is coming from, and simple debridement is included, thus not billable separately. We are also made aware these codes may be done in addition to other major procedures, such as radical excisions in order to close the wound site, this was good information to know as now we will be aware to look for grafting done in the operative note of major procedures on the skin and muscle.
Instructions also tell us to code for repair of the donor site separately if done.
This was all good information to confiscate for evidence in order to prove our case. Looking down at the codes the first thing we notice is they come in sets of two; a primary procedure and an add-on. The next thing was the first three sets of codes 15000-15121 included two sets of measurements; 100 square centimeter and percentages. The codes state the “percentage” measurement is for infants and children thus deductive reasoning tells us the “100 sq cm” measurement would be for adults. Looking back through the guidelines for this section, the last paragraph confirms our deduction; “The measurement of 100 sq cm is applicable to adults, and children age 10 and over; percentages apply to infants and children under the age of 10”. These was great information as we now have established age parameters and know we need to check the date of birth for our patient first before trying to determine the correct codes.
The next thing we took note of is that each set of codes was broken down by what type of graft they represented. The exception was the first two codes 15000-15001. These were used to report “preparation or creation of the recipient site”. We made note of this for later.
In order to extract the correct codes from our report, a thorough understanding of what each of these grafts represented was definitely needed. We pulled out an illustration of the skin anatomy and turned to our simple medical dictionary.
Code 15050 is used to report a “Pinch Graft” (ouch.. I’m awake) This is defined as a “small free skin graft obtained by lifting the skin with a needle to form a cone, which is cut across the base resulting in a base 2-4 mm in diameter with a full thickness of skin at the center; a number of them are placed at intervals on an open wound”. Interesting enough, was this was a stand alone code, with no add-on pair. It was also coded for a defect limited to 2 cm in size. Okay so this is a pretty small graft then, like the tip of a finger.
The rest of the codes were broken down by type of graft but interestingly enough more than one set reported the same type of graft. Codes 15100-15121 report “Split Thickness” grafts. These are defined as; “a skin graft consisting of the epidermis and a portion, or about 1/3rd of the dermis.
Codes 15200-15261 reported “full thickness” skin grafts or “a skin graft consisting of the epidermis and the full depth of the dermis.
The last two sets of codes report “Allografts” or healthy skin taken from a cadaver, and Xenograft” or biological wound dressing or healthy skin from a pig.
Lastly breaking down the two types of graft codes the difference in individual codes is the anatomical site of repair.
With all this information the coding looked pretty cut and dry, so why were these particular codes falling victim to our pesky perpetrators?
After much investigation our coding microscope discovered the problem lay specifically with the Split Thickness and the preparation codes. These were the only codes that included both “sq cm AND percentage measurements” .All other codes only included measurements for “sq cm”. The other difference was the amount of “sq cm” the different types of graft included. Split Thickness included measurement of up to “100 sq cm” The Full Thickness only included up to “20 sq cm”.
Upon careful inspection of the Split Thickness codes, 15100-15121, the primary procedure reported “first 100 sq cm or less”. The add-on codes very specifically stated “each additional 100 sq cm or 1%…. or any additional part thereof: That made it easy to understand, if we had 145 sq cm split thickness repair or the trunk, we could code 15100 x 1 and 15101 x 1. What threw the whole thing off were the “preparation site codes 15000 – 15001. These codes were reported for 100 sq cm but did NOT included the verbiage “or any part there of”. The add-on code specifically, only states “each additional 100 sq cm”. Did this mean that if we did preparation of our 145 sq cm graft site, we could not bill the additional 45 beyond the first 100?
Our investigative experience told me to check our CPT Assistant issues first, and once again our answer was spelled out in black and white. May 1999 Volume 9 Issue 5, a coder asked the exact same questions and the answer:
“Code 15001 includes excision of wounds tht involve additional centimeters beyond the initial 100 cm. up to and including the additional 100 sq. cm…. and/or for the remaining sq cm”.
With this said our culprits are once again foiled. Even though the verbiage isn’t in the actual CPT, the bottom line is what is good for the Goose (split thickness grafts) is once again good for the Gander (site preparation).
As a note, hold on to this article for future reference, because just when we finally have an understanding of graft codes the 2006 CPT has added to, revised and changed this whole section. Starting January 1st we will now have graft codes from 15040 – 15431 and this is only the additions.
Until next time, happy sleuthing coders and see you at the CSI Desk.
The Coding Sleuth
--Tara