Dermatology Coding Alert

Append modifiers -59 and -51 to separate related codes

When a dermatologist performs multiple procedures in a single visit, you'll likely use either modifier -59 or modifier -51 to prove that you aren't trying to double-dip on your claim.

Take a closer look at these modifiers, with the help of some coding experts, and follow these helpful hints to report them correctly on your claims.

Modifier -59 (Distinct procedural service) identifies a procedure that is distinctly separate from any other procedure or service the dermatologist provides on the same date. Note: Use modifier -59 only when no other descriptive modifier (that is, an anatomic modifier or a staged-procedure modifier) fits the documentation.


Case example: Apatient comes to your dermatology clinic for a suspicious lesion on her face. Under examination, the dermatologist decides to perform a biopsy. While examining the patient, the dermatologist also discovers several actinic keratoses (AK). With proper consent from the patient, the dermatologist uses cryosurgery to freeze and remove the AKs.

You should report 11100 (Biopsy of skin, subcutaneous tissue and/or mucous membrane [including simple closure], unless otherwise listed; single lesion) with modifier -59 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) with modifier -51 (Multiple procedures), advises Carole Violette, CPC, CDC, clinical manager at Yakima Valley Dermatology/ Derm Attractions in Yakima, Wash.

Modifier -51 is rarely used anymore, Violette says. The definition of -51 is to reduce the billed amount by 50 percent, she states.

Warning: Never reduce the charge on your bill. Instead, let your insurance carrier do the math. In the case example above, if you reduce the billed amount for 11100, Violette warns, the carrier will reduce your reimbursement again. Very few insurance companies require you to use modifier -51 because there is an automatic reduction.

Explanation: Generally, you should use modifier -59 if the dermatologist performed the procedures at separate sessions or for different reasons, advises HeatherCorcoran, coding manager at CGH Billing Services in Louisville, Ky.

Think of it this way: Modifier -59 tells the payer that the procedures were not components of one another but were actually both medically necessary and separate from one another, Corcoran states.

When your dermatologist operates on a patient with multiple conditions requiring multiple surgeries, you should include modifier -51 on your claim to show that the procedures were indeed separate.

Explanation: Modifier -51 shows the insurance company that the procedures performed were unrelated to each other. Some insurers, Corcoran explains, will append modifier-51 on your code for you. Other insurers, particularly private carriers, insist that you append modifier -51 to your codes when you report them, and if you don't, the payer denies the second procedure. This is one instance where you have to know your insurance company's guidelines before you use the modifier, Corcoran warns.

Remember: When filing claims with modifier -51, make sure you report the code with the highest relative value units (RVU) first. The first code listed on the claim is the only code that will be reimbursed at 100 percent. Many carriers, Corcoran explains, automatically take the reduction on the lower-priced procedure, but its a good idea to list the highest paid procedure first, just in case. For example, first bill 11100 for debridement, which pays approximately $91 with modifier -51, and then 17000 for destruction of AKs second because it reimburses approximately $67.