General Surgery Coding Alert

Question: I noticed that CPT includes modifier -51 for "multiple procedures." I never append this modifier when reporting multiple procedures (such as same-day bariatric surgery and cholecystectomy) and have never had difficulties with the payer. Am I facing a possible audit?

Pennsylvania Subscriber

Answer: More than likely, your payer doesn't require modifier -51 (Multiple procedures), and you are in no danger of an audit because you have failed to append the modifier to multiple procedure claims.
 
Many payers, including the majority of Medicare carriers, use software that automatically detects second and subsequent procedures and reimburses them accordingly, thereby making modifier -51 unnecessary. You should check with your individual payer for its guidelines, however. As always, request the payer's instructions in writing: Documentation is your best defense if your billing methods are questioned.
 
If your payer does require modifier -51, you must consider several factors before appending it.
 
For example, you should not use modifier -51 with any codes notated in CPT with a "x" or "+" (these codes are also listed in appendix "E" of CPT). Such codes are "modifier -51 exempt" because the relative value units assigned to them already take into account their status as "additional" procedures. And you should not append modifier -51 to E/M codes.
 
Also, because payers reduce fees for "subsequent" procedures, you should always choose the highest-valued code as the primary procedure and attach modifier -51 to the lesser-valued procedure(s).
 
For example, if the surgeon performs chole-cystectomy (47600) due to cholelithiasis during bariatric surgery (43846, Gastric restrictive procedure, with gastric bypass for morbid obesity; with short limb [less than 100 cm] Roux-en-Y gastroenterostomy), you would report 43846, 47600-51. Documentation must support each code independently, outlining the medical necessity for each procedure.
 
You should append modifier -51 to 47600 because it is the lesser-valued procedure. The payer should reimburse 43846 at full value and pay for 47600 at a reduced rate (usually 50 percent of the standard fee).