General Surgery Coding Alert

Although the coding itself is straightforward there is only one Unna boot code this does not necessarily mean that reporting this service will be problem-free. An Unna boot is a medicated dressing that surgeons use to treat varicose leg ulcers, which may occur due to increased venous pressure from venous insufficiency or other outflow problems. Unna boots also are used to manage lymphatic edema and sometimes are used for sprains, strains, minor fractures and, sometimes, as a protective bandage for grafts on wound burns.

Application of an Unna boot is reported using 29580 (Strapping; Unna boot), which consists of layering a bandage impregnated with Unna paste (gelatin, glycerin and zinc oxide) on the leg ulcer until the bandage becomes semirigid. The combination of pressure and medication aids the healing process.

Multiple treatments typically are required, usually once a week and sometimes more frequently, says Elaine Elliott, CPC, a general surgery coding and reimbursement specialist in Jensen Beach, Fla.

Tip 1: Only significant and separate E/M services should be reported on the same day as Unna boot application. Because Unna boots are applied during a series of visits, E/M services (for example, an established patient visit) should not be reported when the patient comes for scheduled treatment unless the patient has another problem. In such cases, modifier -25 (Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure or other service) should be appended to the E/M code.

The appropriate E/M service code may be reported separately for the initial assessment of the condition that led to the decision to apply the Unna boot.

Note: Most procedures, including Unna boot strapping, incorporate a preprocedure evaluation that involves routine follow-up care. A second diagnosis, although not necessary for Medicare carriers, always is helpful by indicating why the visit was separate and significant.

Although casts, splints and other supplies may be separately payable, Medicare does not include Unna boot dressings in the same category. Therefore, supplies (bandages, straps and paste) should not be reported separately to Medicare carriers, and most private carriers are likely to follow Medicare's lead.

Medicare considers the Unna boot a dressing rather than a cast and says it is included in 29580 the application code Elliott says.

Note: The procedure is valued at 1.23 relative value units when performed in a nonfacility setting.

Some patients (those with venous stasis ulcers [454.0] for instance) may require debridements. In such cases a separate debridement code (typically 11040 Debridement; skin partial thickness; 11041 skin full thickness; 11042 skin and subcutaneous tissue; 11043 skin subcutaneous tissue and muscle; or 11044 skin subcutaneous tissue muscle and bone) may be reported.

If the Unna boot is applied by a nurse or another nonphysician practitioner (NPP) such as a physician assistant or a nurse practitioner these debridement codes should not be reported even under "incident to " says Marcella Bucknam CPC a general surgery coding and reimbursement specialist and a coding instructor at Clarkson College in Omaha Neb.

Instead Bucknam says the NPP's services should be reported using 97601 (Removal of devitalized tissue from wound[s]; selective debridement without anesthesia [e.g. high pressure waterjet sharp selective debridement with scissors scalpel and tweezers] including topical application[s] wound assessment and instruction[s] for ongoing care per session) or 97602 ( non-selective debridement without anesthesia [e.g. wet-to-moist dressings enzymatic abrasion] including topical application[s] wound assessment and instruction[s] for ongoing care per session).

Tip 4: Bilateral treatments may be reported. If Unna boots are applied to the left and right leg the procedures should be reported to Medicare carriers by appending modifier -50 (Bilateral procedure) to 29580 says Elliott. Some Medicare carriers may request that modifiers -LT (Left side) and -RT (Right side) be used instead. Others such as Empire Medicare Services the Part B carrier in New Jersey and parts of New York state instruct providers to use -LT or -RT if only one side is performed and to append modifier -50 if the Unna boot is applied bilaterally.

Many private carriers also may require the procedures to be reported as follows: