Podiatry Coding & Billing Alert

Medical terminology will help you code these conditions more easily.

Your podiatrist is likely to see patients with a variety of foot and ankle ulcers. In Podiatry Coding Alert Volume 15, Number 4, we looked at code choices for pressure ulcers — injuries to the skin and underlying tissue caused by pressure to the affected body area over time.

Now, we turn our attention to another kind of ulcer: nonpressure ulcers caused by such conditions as diabetes or varicose veins that create nonhealing wounds. When this happens, you must be vigilant in choosing the most accurate diagnosis code.

Check these key tips for accurately reporting lower extremity nonpressure ulcers.

Know Medical Terms to Find the Right Code

Some of the ICD-10-CM codes for nonpressure ulcers use terminology that you must know if you want to find the right code. One key term involves “necrosis,” as noted in many of the following codes:

• L97.311 (Non-pressure chronic ulcer of right ankle limited to breakdown of skin)
• L97.312 (…with fat layer exposed)
• L97.313 (…with necrosis of muscle)
• L97.314 (…with necrosis of bone)
• L97.315 (…with muscle involvement without evidence of necrosis)
• L97.316 (…with bone involvement without evidence of necrosis)
• L97.317 (…with other specified severity)
• L97.319 (…with unspecified severity)

To select the right code, you must be able to identify from the medical record whether the patient’s skin experienced necrosis. Necrosis refers to how healthy the wound is and is a sign that there is a vascular issue that likely leads to inadequate perfusion, or blood flow, to the wound, according to Jordan Meyers, DPM, partner at Raleigh Foot and Ankle Center and consultant at Treace Medical Concepts, Inc. in Raleigh, North Carolina. So, if you see the words “dead tissue” in the podiatrist’s notes, that could indicate that necrosis is present. But always query the provider if you’re unsure.

In addition, you should watch out for the key descriptor terms “with bone involvement” versus “with muscle involvement.” This distinction helps define the depth of the wound and how much treatment may be involved, according to Meyers. The deeper the wound, the deeper the problem and the higher risk of infection or need for surgery. This means it is vitally important for you to look for these terms to choose the most accurate diagnosis code.

Note: The podiatrist may not always explicitly use the terms “with muscle involvement” or “with bone involvement.” Instead, they might document the muscle or bone name, such as, “Non-necrotic diabetic ulcer of the left foot which has invaded 2 cm of the flexor digitorum brevis muscle.” This indicates that the ulcer is not necrotic and involves the muscle.

For instance, if the podiatrist documents a non-pressure ulcer of the right foot with no necrosis but which does have muscle involvement, you’ll report L97.415 (Non-pressure chronic ulcer of right heel and midfoot with muscle involvement without evidence of necrosis).

Remember ‘Code First’ Notation in Diabetic Ulcers

When you look at the nonpressure ulcer codes, you’ll note that the majority of them have a “code first” disclaimer attached: “Code first any associated underlying condition, such as diabetic ulcers (E08.621, E08.622, E09.621, E09.622, E10.621, E10.622, E11.621, E11.622, E13.621, E13.622).”

“Code first” indicates that an additional code is required and must be listed first. The order you use matters, so always list the diabetes code first, such as E10.621 (Type 1 diabetes mellitus with foot ulcer or E11.621 (Type 2 diabetes mellitus with foot ulcer) and then the ulcer code on the claim form.

“Use Additional Code” Complicates Things Further

Just as the order matters when you see “Code first,” the order in which the codes are listed is important when the ICD-10-CM manual instructs you to “Use additional code.” Under E11.621, the directions say to “Use additional code to identify any insulin use (Z79.4)” and “Use additional code to identify oral hypoglycemic use (Z79.84).”