Internal Medicine Coding Alert

Why your 11400-11646 reporting may not measure up

When your internist excises a lesion (11400-11646), you could be losing $275 per claim if you don't know the lesion's pathology, location and measurement, coding experts say.

Determine Lesion Type

If your internist is a primary-care physician, he or she may regularly treat lesion removals. But before you can code the excision, you have to know whether the lesion is benign or malignant.

For benign procedures, you should choose a code from the 11400-11471 series. When the physician excises a malignant lesion, you should use the 11600-11646 series codes. Typically, the physician will determine a benign or malignant state based on a pathology report.

"Our office waits for the pathology report before billing any lesion excision procedures," says Pat Larabee, CPC, CCP, a coding specialist at InterMed, a multi-specialty healthcare network in South Portland, Maine.

Warning: You could face denials or cost a patient his or her insurance coverage if you attempt to code a lesion excision without a pathology report, says Susan Callaway, CPC, CCS-P, an independent coding consultant and educator in North Augusta, S.C.

Example: Although you don't have the pathology report, you know the physician suspects that the lesion is malignant. Therefore, you report 11600 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 0.5 or less), and link diagnosis code 172.5 (Malignant melanoma of skin; trunk, except scrotum) to the procedure. When pathology comes in, however, you learn that the lesion was benign.

In addition to incorrectly coding the procedure, you have classified the patient with a cancer diagnosis he doesn't have, which could prevent him from obtaining insurance in the future, Callaway says.

Find Lesion Location, Then Pick the Code

But don't stop with the pathology report. Once you've narrowed down your coding selection to the 11400-11471 or 11600-11646 series, you have to know the lesion location to select the right code. You should review the physician's documentation to determine where on the patient's body the lesion was located, says George Ward, a billing supervisor for South of Market Health Center in San Francisco.

CPT Designates 3 Body Areas

Helpful: CPT breaks down excision procedures for both benign and malignant lesions into three body areas:

1. Trunk, arms or legs. When you find these areas in the documentation, make sure you report a code from either the 11400-11406 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere], trunk, arms or legs ...) or the 11600-11606 (Excision, malignant lesion including margins, trunk, arms, or legs ...) series.

2. Scalp, neck, hands, feet, genitalia. For a lesion located on these body parts, use either 11420-11426 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere] ...) or 11620-11626 (Excision, malignant lesion including margins ...).

3. Face, ears, eyelids, nose, lips, mucous membrane (benign only). To correctly report these lesions, assign 11440-11446 (Excision, other benign lesion ...) or 11640-11646 (Excision, malignant lesion ...).

Let Measurements Guide Your Coding

Often your internist's lesion measurements make all the difference when you choose an excision code. Make sure you look in the documentation for the measurements before coding the excision, Larabee says.

CPT guidelines require that prior to the procedure, physicians measure the lesion's diameter in addition to the "most narrow margins" the physician needs to make the excision, says Brett Baker, third-party payment specialist for the American College of Physicians-American Society of Internal Medicine in Washington, D.C. 

"When the lesion is malignant and the margins are not clear, our internal medicine physicians will usually refer the patient to a dermatologist for complete excision," Larabee says.

In such instances, you should report the appropriate E/M code (99201-99205, 99211-99215), depending on the physician documentation.

How it works: A lesion's margins equal 0.4 cm, and the lesion's diameter is 1.7 cm. This means the physician excised a 2.1-cm lesion.

Lesson learned: Measurements are important because CPT breaks down the appropriate codes based on the "excised diameter" of the lesion. For instance, the physician removes a 2.1-cm benign lesion from a patient's neck. In this case, that size lesion requires 11423 (... excised diameter 2.1 to 3.0 cm).