Primary Care Coding Alert

Modifiers -59 (Distinct procedural service) and -51 (Multiple procedures) have heads spinning, and the convoluted language in CPT offers little relief to coders - but experts say the key to the confusing modifiers is understanding the definition of "distinct."

"Modifier -51 is straightforward; FP coders use it a lot to indicate multiple procedures," says Marie Felger, CPC, an American Academy of Professional Coders (AAPC) certified coding instructor with Joy Newby & Associates Inc. in Indianapolis. "But the -59 is what slips them up. Distinct can mean a lot of things - separate site, separate encounter." Often coders use a -51 when they should use a -59 and vice versa.

Because modifiers -51 and -59 are for surgical procedures, family practices most often use them when dealing with lesion removal and biopsy, Felger says.

"Attaching a modifier -51 tells the insurer that you performed more than one surgical service at the same session," says Joy Newby, LPN, CPC, president of Joy Newby & Associates Inc., a reimbursement consulting company in Indianapolis.

For example, an established male patient presents to the FP with lesions on his chest and hand, and the physician removes them during the same visit. Both 11421 (Excision, benign lesion, except skin tag [unless listed elsewhere], scalp, neck, hands, feet, genitalia; lesion diameter of 0.6 to 1.0 cm) and 11401 (Excision, benign lesion, except skin tag [unless listed elsewhere], trunk, arms or legs; lesion diameter 0.6 to 1.0 cm) should be billed. Attach modifier -51 to 11401.

"You attach the modifier -51 to the lesser-valued service because the payer will reduce the fee for the code with the modifier, and you want to be paid in full for the more expensive procedure," Newby says. Carriers will usually pay about 50 percent or less of the second procedure. Newby advises coders to bill the full fee for each procedure because usually the payers will automatically reduce the fee with the -51 modifier. Keep in mind that requirements for -51 vary from carrier to carrier.

Attaching modifier -59 to a code tells the insurance company to unbundle two procedures that normally cannot be paid together, says Daniel S. Fick, MD, director of risk management and compliance for the College of Medicine faculty practice at the University of Iowa in Iowa City. For example, in the morning the FP removes a skin tag from a patient's back. Later that afternoon, the patient returns with a broken right great toe from falling down some stairs. Report 11200* (Removal of skin tags, multiple fibrocutaneous tags, any area; up to and including 15 lesions) and the appropriate fracture care code (e.g., 28490, Closed treatment of fracture great toe, phalanx or phalanges; without manipulation) with modifier -59 attached to the fracture care code to indicate that it was done at a separate session.

"You've done two services, but not at the same encounter, so the -51 does not apply," Newby says. "You attach modifier -59 in this case to show that the services are separate."

Normally, insurers apply multiple surgical reductions when two surgical procedures are performed in one day, but the modifier -59 tells the payer to unbundle these services because they were performed during separate sessions and to reimburse them appropriately. Some payers do not recognize modifier -59, so be sure to check with your carrier.

Modifier -59 usually goes on the lesser-valued of the two bundled services. However, sometimes attaching modifier -59 to the code with the highest allowable RVU is appropriate if that code is a component of the comprehensive code. Modifier -59 is typically appended to the code (regardless of value) that would otherwise be denied or is a component of another, more comprehensive code. You can only use modifier -59 to unbundle services that have a "1" indicator next to them in the Correct Coding Initiative (CCI) edits.

To understand the basics of CCI edits, see the beginning of the article "CCI Update: New CCI Edits Affect Vaccination and Wound Care" in the June 2002 issue of Family Practice Coding Alert.

Occasionally, you can use both modifiers at the same time. For example, the FP performs a biopsy of a lesion on a patient's arm and excises a benign lesion on the neck during the same visit. You would report 11100 (Biopsy of skin, subcutaneous tissue and/or mucous membrane [including simple closure], unless otherwise listed [separate procedure]; single lesion) and 11420 (Excision, benign lesion, except skin tag [unless listed elsewhere], scalp, neck, hands, feet, genitalia; lesion diameter 0.5 cm or less) and append modifier -51 and modifier -59 to the biopsy code.

Modifier -51 is attached to the 11100 because it is the lesser-valued procedure, while -59 is attached to that code because the biopsy is a component of the excision. The -51 indicates that two procedures were performed, and the -59 indicates that they were performed on two separate lesions. "Without the -59, the payer could assume that both biopsy and excision were done on one lesion, and they wouldn't pay for that," Newby says. The use of both codes illustrates a multiple procedure that is normally bundled but should be unbundled because it was performed on two separate sites.

Note: Test your knowledge of -51 and -59 with scenarios in article 4.