Dermatology Coding Alert

Question: Should I always append modifier 59 to the lower-valued code of an NCCI bundle?


Washington Subscriber

Answer: In most cases, you append modifier 59 (Distinct procedural service) to the lower-valued code, but that's not always the case.

A better rule to follow is this: Append modifier 59 to the column-two code or the component code of a code pair edit.

The National Correct Coding Initiative (NCCI) mutually exclusive code list contains edits consisting of two codes (procedures) that a physician cannot reasonably perform together based on the code definitions or anatomic considerations.

Each edit consists of a column-one (comprehensive) and column-two (component) code. If you report both codes on the same service date for one beneficiary without an appropriate modifier, Medicare will pay only the column-one code.
 
When clinical circumstances justify appending a modifier to the column-two code of a code pair edit, the carrier may allow payment of both codes.

Example: A dermatologist removes an underarm skin tag and destroys a benign lesion on a patient's back.

NCCI considers 11200 (Removal of skin tags, multiple fibrocutaneous tags, any area; up to and including 15 lesions) and 17000 (Destruction [e.g., laser surgery, electrosurgery, cryosurgery, chemosurgery, surgical curettement], all benign or premalignant lesions [e.g., actinic keratoses] other than skin tags or cutaneous vascular proliferative lesions; first lesion) mutually exclusive procedures and bundles 11200 into 17000.

Code 17000 is the comprehensive (column-one) code and 11200 is the component (column-two) code.
 
Because the dermatologist performs the procedure on different lesions, clinical circumstances allow you to report both codes.

You should attach modifier 59 to the component/column-two code: 11200.

Problem averted: Understanding the mutually exclusive tables will help you avoid incorrect modifier use. If you based modifier attachment on the codes' values instead of the codes' column designations, you would incorrectly attach modifier 59 to 17000 -- the lower-valued code. (The 2006 National Physician Fee Schedule assigns 1.60 relative value units to the lesion destruction code 17000 and 1.85 RVUs to the skin tag removal code 11200.)

You should instead append modifier 59 to 11200 -- the component and, incidentally, higher-valued code.

Lesson learned: A code's RVUs do not necessarily matter when you deal with mutually exclusive codes.