Part B Insider (Multispecialty) Coding Alert

 But watch out for overlapping global periods

Not only can a physician assistant (PA) serve as an assistant at surgery, but so can an advanced nurse practitioner (ANP), according to a frequently asked questions document posted on the Web by Part B carrier Wisconsin Physicians Service Insurance Corp. 

An ANP's "national certificate must support all services they perform," notes WPS. Also, the state license and hospital rules must both allow the service.  But a registered nurse first assistant (RNFA) cannot be an assistant at surgery, WPS says, because an RNFA isn't the same as a physician assistant.

It's usually up to individual states to decide whether an ANP can serve as assistant at surgery, says Stephanie Collins, director of special projects at Medical University of South Carolina in Charleston, SC. When a PA or ANP is serving as assistant at surgery, he or she is usually under the direct supervision of the surgeon the entire time, Collins notes.

When an ANP or PA is serving as assistant at surgery, you'll usually use the -AS modifier (for Medicare) or modifier -81 (for some other payors), says Marcella Bucknam, HIM coordinator at Clarkson College in Omaha, NE. Some private payors may not cover a PA or ANP as assistant at surgery at all, she notes, and some may credential the non-physician providers separately.

"I know of a lot of practices where the PA or NP does almost nothing but assistant at surgery," says Bucknam. Often, the non-physician practitioner will do all the follow-up care after surgery, including hospital rounds.

Separately, WPS says that if a patient has an unrelated surgery during the 90-day global period of an earlier surgery, then the surgeon should bill the second surgery using modifier -79 (Unrelated procedure or service by the same physician during the postoperative period). A new global period will begin for the second surgery.

Providers often face denials or slow payments for unrelated surgeries during a global period, Collins says. You may want to spell out in a letter the reason for the second surgery, so the carrier or other payor doesn't become confused. You should also watch that patient's claims for a few weeks to see if they're being held up. "With this particular situation, you might have to be more proactive," says Collins.

When billing an unlisted CPT code, the carrier can decide individually whether the procedure has a global period, WPS says in response to another question. If the procedure does, the carrier decides how long the global should be, based on whether the procedure is major (90 days) or minor (10 days), WPS explains.