Key Coding Insights For Skin Conditions And Wounds

By Anthony Poggio, DPM

Given the vast array of dermatological conditions and wounds that we see in our practices, having a strong understanding of commonly used codes for these conditions is essential but not always simple. With this in mind, let’s take a closer look at coding for both common skin conditions such as verrucae and benign skin lesions, as well as coding tips for I&D procedures and wound closure. Standard billing protocols apply for selecting the appropriate E/M level for services for dermatological conditions. Similarly, protocols for billing E/M services with procedures performed on the same day as the E/M service and the use of clarifying modifiers apply. Charting for dermatological lesions should include the location and number of lesions. The size of the lesion is very important in selecting the appropriate CPT code within a code series. Many skin lesions require multiple treatment sessions or modalities. Therefore, documenting the status of the lesion (healing, not healing, change in appearance, etc.) is important to justify your billing. Describing the lesion is important not only from a billing perspective but for medical-legal reasons as well, especially if there is any suspicion of a malignant skin cancer. Keep in mind that it is very common for several dermatological lesions to be present, even in a relatively small area as the foot. One can group the coding for multiple lesions within a code series or bill them as individual lesions. Using -51 modifiers to designate multiple lesions may be required. Also consider the use of T digital modifiers, RT/LT or –59 modifiers to further clarify your billing per insurance company guidelines. Skin closure of wounds is often incorporated as part of a long-term treatment plan or as a “staged” procedure. Consider the use of modifier –58 in this case. What You Should Know About Coding For Verrucae There are varied treatments for verrucae. If the patient is on a home treatment regimen, then E/M services may be payable to monitor the treatment course. Applying a home treatment medication in the office is not payable separately from the E/M service. When it comes to employing office-based medications (such as monochloracetic acid, canthrone, etc.), a CO2 laser and cryosurgery, these modalities fall under the “destruction” classification and are properly coded with the 17000 series codes. Such treatments are based upon the specific number of lesions you treat. If you treat a single lesion, use CPT 17000. If you treat more than two lesions, use both CPT 17000 and CPT 17003 codes. If you are dealing with more than 15 lesions, use only CPT 17004. Keep in mind that any local debridement of previously treated tissue would be included in the E/M or destruction procedure performed on that day. There is no extra allowance for use of the laser machine. Blunt curettage is another treatment option for verrucae. This requires local anesthesia and blunt enucleating through the skin layers but not past the basement membrane. Usually, no suturing is required. Since there is no potential for closing such a wound, using the CPT 11420 series for excision of a benign lesion is not appropriate. It is best to code the blunt curettage treatment option with the 17000 codes. Coding Tips For Skin Lesions Treatment of benign and malignant skin lesions can include chemosurgery, laser surgery, cryosurgery and curettage. Since no specimen may be available after the procedure, one should clearly document the appearance of the lesion or biopsy prior to destruction. As with verrucae, use CPT code series 17000-17004 for benign lesions. For the destruction of malignant lesions, use CPT code series 17271-17274. Coding for a malignant lesion is based upon the size of the lesion and each lesion you treat is billed individually. For destruction of benign lesions, coding is based upon the total number of lesions. It is best to use the code series CPT 1142X and CPT 1162X when it comes to the respective coding for the excision of benign or malignant foot skin lesions. If you are unsure whether the lesion is benign or malignant, it is advisable to wait for the pathology report before submitting a claim rather than submitting a corrected claim later. Selecting the proper code is based upon the size of the lesion. In the past, one would measure the widest margin of the lesion and use the appropriate code based upon that measurement. After 2003, the proper way to code skin lesion excisions is to measure the widest width of the lesion and then add the clear border/margins required on both sides of the lesion. This may affect the eventual CPT billing code you use as this new approach to coding these lesions allows the proper billing of a higher code. For example, if one excises a 1.2 cm lesion with 2 mm margins on both sides, the proper “size” of the lesion is 1.2 cm + .2 cm +. 2 cm. This adds up to a 1.6 cm lesion. When You Need To Obtain A Biopsy Diagnosing skin lesions can be difficult as one may often see an unclear clinical picture. In these cases, a biopsy is required. One can bill a biopsy of skin and subcutaneous tissues by using the CPT code series 11100 for a single lesion and adding CPT 11101 for each additional (separate) lesion. Closure of the biopsy is included in the procedure fee allowance. If you perform a shave biopsy in which you essentially remove the entire lesion, use the CPT 11305-11308 code series. For a biopsy of the toenail/nail unit, one can bill this with the CPT code 11755. This code description includes biopsy of the nail plate, nail bed, nail matrix and adjacent hyponychium, and nail folds. There is some controversy as to the proper use of this code for a biopsy of the nail itself. One should not use this code when simply clipping a loose or crumbling portion of nail for KOH or DTM testing of the nail. There may be specific instances when a more definitive diagnosis is necessary and one needs a PAS stain. In these cases, it will be necessary to remove a larger and more proximal piece of nail. Clearly document why such a definitive test is required as opposed to other types of fungal nail testing. Check with the specific insurance company regarding what it requires for documentation of onychomycosis or tinea. Routinely performing nail biopsies as a means of obtaining fungal specimen is of questionable medical necessity and may result in audits. How To Handle Coding For Common Nail Conditions While palliative care for mycotic nails is beyond the scope of this article, it is important to differentiate between nail trimming and nail debridement. Each Medicare carrier will have its own coverage guidelines and language for these definitions. Generally, the debridement of a nail is a procedure that is intended to remove excessive material (e.g., to significantly reduce nail thickness/bulk) or excessive curvature from a clinically and significantly thickened dystrophic or diseased nail. Trimming of a nail is a procedure that is intended to reduce only the length of the nail. One can perform this service on a normal nail or a dystrophic nail. Use CPT 11720 when debriding a total of one to five nails and 11721 for debriding greater more than six nails. Again, one may trim a dystrophic nail (G0127) or a non-dystrophic nail (11719). There are other options for treating fungal nails and tinea. It is perfectly acceptable to schedule follow-up visits to monitor the progress of oral and topical antifungal treatment courses. Possible treatment protocols may change based upon the success or failure of other treatment modalities. Such consideration and evaluations constitute an E/M service. Obviously, the treatment of fungal nails is a long process and nothing happens quickly. Therefore, medical necessity and reason dictate what is an appropriate time frame to see a patient back to monitor their treatment progress. Debridement of nails simply as an adjunct to oral or topical therapy is not payable separately from the E/M service unless the patient meets “at-risk” or painful nail criteria. In this case, Medicare or other insurance carriers’ nail care policies would be in effect. Check with the various carriers to obtain the proper billing protocols for these nails. Check for regulations regarding the use of specific qualifying secondary diagnosis and Q modifiers that need to be listed on the claim form. How To Differentiate Between Ulcer Debridement And Skin Debridement Codes When considering the ulcer debridement code (CPT1104X) and the skin debridement code (CPT11000), be aware that both of these codes series seem to overlap as they both “debride necrotic or devitalized skin.” Some Medicare carriers in the past had put unfair restrictions on debridement of ulcers. As a result, clinicians often used CPT 11000 for ulcer debridement. For the common ulcers we treat in the feet and ankles, the best code series to use is the CPT 1104X series. When debriding more diffuse eczematous, pustule-type lesions or other superficial skin infections, using CPT 11000 is appropriate. It is generally not appropriate to bill CPT 11001 as both feet and ankles cannot add up to more than 10 percent total body surface. When charting for these conditions, be very specific and detailed about the description of the lesion/wounds that are being treated. For the more classic decubitus, venous, arterial and neuropathic ulcers, make sure the chart indicates the size and depth of the wound, and, most importantly (from a billing perspective), what tissue was actually debrided. This will determine the proper code to select within the CPT 1104X series. Keep in mind that CPT 11043 and CPT 11044 have a 10-day global period. What You Should Know About Coding For Burns And Skin Grafts For the local and surgical care of a burn area, use CPT code range 16000-16036, not CPT 11000. When using these codes, list the percentage of body surface involved and the depth of the burn. These codes pertain to the burn itself and do not necessarily include other procedures that may be required in order to treat other involved tissues or structures. There are many types of skin grafts (split thickness grafts, full thickness grafts and flaps) and they are listed within the CPT code ranges 15000 through 15770. There are specific CPT codes within this range for allografts and xenografts. While one would use CPT 15342 when applying bilaminate skin substitutes, be sure to verify that the material you are placing on a wound constitutes a bilaminate skin substitute. There are some materials available that may be presented as bilaminate skin substitutes or even xenografts but are deemed no more than topical dressings by some insurance carriers. Do not rely solely on the manufacturer’s recommendation. The item may be reimbursable as a supply but the application of the item may not be reimbursable as a “skin graft.” If additional surgical care is required to prepare the wound base for eventual skin grafting, use CPT 15000. One may not use this code for “preparing” the wound base for other dressings, as mentioned in the above paragraph. What About I&D Procedures? For incision and drainage or foreign body removal in skin and subcutaneous tissue (including nails), use the code range CPT 10040 through 10160. Within these codes, there are sub-classifications for “simple versus complicated.” There are no specific guidelines or definitions of these two terms. Use your best clinical judgment and clearly document why a particular scenario requires more extensive work (hence complicated) than is usually required. For deeper incision and drainage procedures, use CPT 28001 to CPT 28005 codes. For incision and drainage of complex postoperative wounds, one may use CPT 10180. For some carriers, especially Medicare, such postoperative care may still be included in the overall global care of the patient. Therefore, such services may not be payable separately unless the patient has to return to the operating room for care. In this case, one can bill this CPT code with a –78 modifier. Check with the appropriate carrier for its guidelines on this code. Getting A Handle On Coding For Wounds Repair of a skin wound is listed as simple (CPT 12001-12007, intermediate (CPT 12041-12047) and complex (CPT13131-13133). Clearly chart the length, depth and any other associated damage of the wound. When closing a wound with adhesive strips only, you should bill it as an E/M service only and not with a skin repair code. Epidermis, dermis and subcutaneous wounds that involve a single layer of closure are defined as “simple.” Repairs involving multiple layered closure or single layered closure of a heavily contaminated wound are considered “intermediate.” This would include cleaning the wound of particulate matter and minor debridement. Repairs involving additional work beyond multiple-layered closure such as tissue undermining, significant tissue debridement and cleaning are considered “complex.” With such wounds, additional wound care of traumatized or exposed nerves, blood vessels tendons, muscle, etc., may be payable separately. Check the CPT book for the specific definitions when billing repair codes. When it comes to a simple wound repair of a dehiscence, one can code this with CPT 12020-12021. Many insurance carriers may include such care within the global care of the principal surgical procedure so it may not be payable separately. Check the global days associated with the principal procedure. Many of the skin repair and other dermatology-related codes have only a 10-day global period. Therefore, these codes may be payable if care is required after that time allotment. In regard to repair or secondary closure of surgical wounds/dehiscence that requires more complex repairs, one can code this with CPT 13160 as appropriate. Other Codes You Need To Know When treating various foot deformities, it may be necessary to perform additional plastic surgery procedures to facilitate closure or assist in correcting a deformity such as a contracted digit. Examples of plastic surgery closures include V-Y skin lengthening, Z-plasty and other rotation and advancement flaps. One should be sure to clarify the need for such procedures on the chart. For these procedures, it is appropriate to use CPT 14040-14041. One can bill this in addition to other procedures such as an arthroplasty. Clinicians should not bill these codes as add-on codes for incidental skin closing procedures including those for traumatic wounds and lacerations. Coding for callus treatment varies by insurance carrier. Medicare allows clinicians to use the CPT code series 11055 to 11057 for the care of calluses/tylomas in the “at-risk” patient only. Depending on your local Medicare carrier policies, one may use CPT 11040 for the debridement of certain painful and keratotic lesions. Check with your Medicare carriers to obtain the proper billing protocols for these lesions. Also check for regulations regarding the use of specific qualifying secondary diagnosis and Q modifiers that may need to be listed on the claim form. Dr. Poggio is a California Podiatric Medicine Association Liaison to the National Heritage Insurance Company and a medical consultant to HealthNet Insurance Company. Dr. Poggio is a member of the American College of Podiatric Medical Reviewers and is board-certified by the American Board of Podiatric Medicine and the American Board of Podiatric Orthopedics.

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