READER QUESTIONS: Nix Modifier 51 for ASC

Question: If the doctor does more than one identically coded procedure, should I report a quantity of “two,” or should I report two separate line items with modifier 59 or 51? I’m coding for an ASC.


California Subscriber


Answer: Unless a payer explicitly requires modifier 51 (Multiple procedures), you should not report it for procedures performed in an ambulatory surgical center (ASC). In Appendix A of the CPT book, you’ll see that modifier 51 is absent from the list of modifiers for outpatient and ASC billing. 

Whether you should report the same code twice (with a modifier) or one code with a quantity of “two” depends on the payer. The best solution may be to contact all your major insurers and ask them about their requirements. Note: Medicare will not take units for CPT codes, so you would have to report two line items. If a code description states “each” and you are reporting two line items, then you don’t need to append modifier 59 (Distinct procedural service) to the second code.

Remember: You’ll need to append modifier SG (ASC facility service) to all CPT codes that you’re billing to Medicare, unless they are implant codes. Visit your fiscal intermediary’s Web site and see whether they have an ASC billing guide to help you.