Answer: Local carriers may have different sets of codes that support medical necessity for the application of an Unna boot. However, most coding experts agree that the more specific you can be with the diagnosis code, the better.
The codes that are most often accepted include ankle sprain (845.00), fracture of the foot (825.25), venous insufficiency (459.81), lymphedema (457.1) or stasis ulcer (454.0 and 454.2).
Some coders report problems if they simply report swelling of the limb (729.81) or localized edema (782.3). Although these conditions may respond favorably to treatment with an Unna boot, both are vague and may be rejected.