Count Muscle Groups, Not Individual Injections, for Proper Chemodenervation Coding

When selecting codes to describe chemodenervation injections, be aware that a single muscle does not necessarily count as a “site” or “functional muscle group.” A typical Medicare payor local coverage determination (LCD) states, for instance, “Medicare will allow payment for one injection per site regardless of the number of injections made into the site. A site is defined as including muscles of a single contiguous body part, such as a single limb, eyelid, face, neck, etc.”

Simply stated, proper coding depends on the number of “contiguous” areas — such as an upper limb, trunk or leg — that the provider treats, not the number of actual injections. This is an important distinction because providers commonly inject small amounts (10 to 25 units) of chemodenervation agent at different sites throughout the same muscle group.

You will select an appropriate chemodenervation injection code according to the area(s) the provider treats:

• Anal sphincter: 46505 — Chemodenervation of the internal anal sphincter
• Eccrine glands: Axillae, 64650 — Chemodenervation of eccrine glands; both axillae. Hands and/or feet, 64999 — Unlisted procedure, nervous system. Other area(s), 64653 — Chemodenervation of eccrine glands; other area(s) (e.g., scalp, face, neck), per day. [Note that this code applies “per day,” not per injection, per muscle or muscle group]
• Extraocular muscles: 67345 — Chemodenervation of extraocular muscle
• Extremity muscles: 64614 — Chemodenervation of muscle(s); extremity(s) and/or trunk muscle(s) (e.g., for dystonia, cerebral palsy, multiple sclerosis)
• Facial muscles: 64612 — Chemodenervation of muscle(s); muscle(s) innervated by facial nerve (e.g., for blepharospasm, hemifacial spasm)
• Neck muscles: 64613 — Chemodenervation of muscle(s); neck muscle(s) (e.g., for spasmodic torticollis, spasmodic dysphonia)
• Trunk muscles: 64614

For example, an ophthalmologist provides three separate injections around the area of the left eyelid to treat blepharospasm (333.81). In this case, you would report a single unit of 64612. The muscles of the left eyelid comprise a single “functional muscle group.” The number of individual injections within the muscle group is irrelevant to proper coding.

When reporting multiple units of any code to describe injection to more than one functional muscle group, some payors may require you to append modifier 59 — distinct procedural service to the second and subsequent codes to substantiate that the codes represent services in distinct anatomical areas.

For example, if the provider injects 10 units of botulinum toxin into three different muscles in the right forearm, with 10 additional injections of 10 units each into the muscles of the right lower leg, you would claim 64614, 64614-59. The right forearm (64614) and right lower leg (64614-59) comprise two separate functional muscle groups.

Whether you can report bilateral injections depends on the site(s) the provider injects. For instance, you can bill bilateral injections for facial muscles (for example, the left and right eyelid) and extremities (left and right leg), but you cannot report separate injections to each side of the neck (because the neck muscles comprise a single functional muscle group).

Returning to our first example, above, if the ophthalmologist provides three injections each on the left and right eyes, you may report 64612 with modifier 50 — bilateral procedure. Note that some payors may prefer that you report 64612 on two lines, with modifiers LT Left side and RT Right side appended (e.g., 64612-LT, 64612-RT). Check with your individual payor regarding its preference for indicating bilateral injections.

G. John Verhovshek, MA, CPC, is director of clinical coding communications for the American Academy of Professional Coders (AAPC), the nation’s largest education and credentialing association for medical coders. AAPC provides certified credentials to medical coders in physician offices, hospitals and outpatient centers, and medical insurance companies.