Outpatient Facility Coding Alert

Differentiate modifiers AS and 80 for billing success.

When PAs serve as first assistants during difficult surgeries, coding the assist shouldn’t be as tough as coding the procedure itself.

The following four expert-tested steps can help you nail down your PA’s reimbursement every time he assists a surgeon.

Step 1: Check the Fee Schedule

Each year, as part of the Physician Fee Schedule, Medicare publishes those procedures for which it approves technical surgical assisting (TSA) by a physician, physician assistant (PA), nurse practitioner, or clinical nurse specialist.

If the Medicare Physician Fee Schedule lists a “1” or a “9” in Column U (“ASST SURG”), you cannot report a surgical assistant’s claim for that particular procedure. For example, according to the 2013 Fee Schedule, a “1” in column U for code 27250 (Closed treatment of hip dislocation, traumatic; without anesthesia) means that even if the PA is there assisting, it cannot be separately paid by Medicare.

Important: If the fee schedule lists a “2” in Column U, you can bill a surgical assist. For example, Medicare lists the liver resection codes (47120-47130) as being billable for an assistant at surgery.

If Column U bears a “0,” your documentation will make or break your assistant’s reimbursement odds. When this column lists a “0,” reimbursement for assistants at surgery cannot be paid unless supporting documentation is submitted to establish medical necessity. You should submit your operative report with these claims to demonstrate why the surgeon required an assistant.

Medicare assigns the “0” indicator to the tenotomy codes 26450-26455, so you should only bill for a surgical assistant during these procedures if the surgeon is certain that he can demonstrate medical necessity to the patient’s insurer.

Step 2: Append AS for Medicare Patients

Suppose the surgeon performs an ethmoid sinus removal (31205, Ethmoidectomy; extranasal, total) and asks a PA to serve as first assistant. The surgeon reports 31205, and the PA reports 31205-80 (Assistant surgeon). Medicare pays the surgeon’s service but denies the PA’s claim, even though 31205 bears a “2” in column U, indicating that the assistant should be paid.

Your error: You should append HCPCS modifier AS (Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery) to your surgical code when you bill Medicare for your PA’s assist.

Some companies will not accept the modifier AS, and some will. Medicare always wants the AS, but when you submit your claims to private payers, you may be required to use modifier 80 instead.

Remember: You should still append modifier 80 to your Medicare patient’s surgical assist claims if a physician performs the assist.  Modifier AS only applies when you bill nonphysician practitioner claims to a Medicare carrier.

Tip: A “best practice” is to query your top 20 payers regarding how you should report PA assists, create a file for each payer and file their modifier preferences with their contracts.

Step 3: Verify Whether Residents Are Unavailable 

Although Medicare considers PAs covered providers in all hospitals, the surgical-assisting rules differ in teaching hospitals.

Any hospital with an approved orthopedic residency program cannot have other parties - such as other physicians or PAs - provide services and bill Medicare, because Medicare has already reimbursed the hospital via its residence funding.

Caveat: If a qualified resident isn’t available to assist, Medicare will reimburse your PA’s assist. The primary surgeon must include a Medicare assistant surgeon attestation statement in the operative report.

For example, suppose a hand surgeon performs a thumb fusion with graft on a Medicare patient in a teaching hospital. The hospital does not offer a hand surgery residence training program, so the surgeon brings the practice’s PA to assist him.

The surgeon should report 26820 (Fusion in opposition, thumb, with autogenous graft [includes obtaining graft]), and the PA should report 26820-AS.

Don’t forget: Carrier preference reigns when it comes to modifiers. Some payers prefer that you append modifier 82 (Assistant surgeon [when qualified resident surgeon not available]) in these situations.

Step 4: Confirm Payer Guidelines

Although Medicare generally holds firm to its guidelines, private payers may publish completely different rules for surgical assistants - and some payers may follow Medicare’s lead instead of forging their own paths.

Regence Blue Shield of Oregon, for instance, requests modifier AS for nonphysician surgical assistants, whereas the policy of Blue Cross and Blue Shield of Mississippi expands its scope for modifier AS beyond PAs and NPs, noting that it “will provide benefits for assistant at surgery services when rendered by registered nurse first assistants (RNFA) with a CNOR certification,” as well as certified registered nurse first assistants (CRNFAs).