Practice Management Alert

Do you know when to bill using a physician assistant's ID number and when to bill using the physician's number? If not, you could be costing your practice money.
 
Knowing when to use which number can be very tricky because there is no "universality" among payers concerning this, says Quin Buechner, MS, M.Div, CPC, president of ProActive Consultants in Cumberland, Wis. "Not every insurer issues ID numbers for PAs, and even among those who do, not every insurer follows the same rules," adds Marcella Bucknam, CPC, CCS-P, CPC-H, CCA, coordinator of HIM certificate programs for Clarkson College in Omaha, Neb.
 
Not surprisingly, Medicare's rules about billing with a PA's number are trickier than most payers' rules. That's because billing under the physician's number for services a PA provides "incident-to" the physician's services earns the practice full reimbursement, while billing under the PA's number brings in only 85 percent of the full fee, Buechner says.
 
If you bill under a physician's number when all of the incident-to requirements aren't met, Medicare may think you're out of compliance for inappropriately trying to secure that extra 15 percent. These requirements are extremely complex, Bucknam says, but what it boils down to is this: To bill incident-to, "(1) the physician must be present in the office suite when the patient is seen, (2) the patient must be an established patient who is being treated under the physician's plan of care and (3) the location must be the physician's office." If all three of these criteria are not met, you must bill under the PA's number.
 
The good news is that many other payers aren't as picky as Medicare about incident-to billing, Buechner and Bucknam say. In fact, some insurers don't even assign ID numbers to physician assistants and "essentially allow incident-to billing for any billable service that a PA may do," Bucknam says. Even so, it's usually easier to apply the most stringent set of rules across the board to avoid having to master several protocols, she says. Therefore, many practices use Medicare's incident-to rules for all payers.

What to Do When a PA Assists at Surgery

"When the PA is assisting at surgery, you have another little flip in the system," Buechner says. It doesn't make any sense to bill under the number of the physician performing the surgery if it also appears he's the supervising physician, Buechner say. Doing so results in two charges for the physician - surgeon and assistant surgeon - which will confuse your payer's computers.
 
To avoid confusion, you'll need to find out directly from your carrier how to handle these situations, Buechner says. Medicare and many other payers deem that the assistant service should be billed under that PA's number, accompanied by a modifier to indicate the assist, Bucknam says. "Medicare wants modifier -AS (Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery) for mid-level assists," she says. "Some other insurers prefer modifier -81 (Minimum assistant surgeon) or even modifier -80 (Assistant surgeon)."
 
Insurers that do not issue ID numbers for PAs have very different rules, and some won't reimburse at all for PA assists, Bucknam says. "Others want you to bill using the physician's number and modifier -AS or -81. Still others want a comment in field 19 of the CMS-1500 form," she says. Again, to make sure you take the correct approach, you'll need to check with the individual insurer, Bucknam says.