Wiki SA modifier vs AS modifier


Anson, TX
Best answers
AS modifier out of network payer

I work in a neurosurgery office in Texas. We have 2 mid-levels who are employees of the surgeons & assist in surgeries as well as seen patients in the office.

Some of our contracts are with an IPA that does not credential mid-levels. Because we are a delegated group, we cannot go outside the IPA to contract with the few insurances that we have with them to get in-network status for our mid-levels.

I am being told (by the IPA) that when billing for mid-level surgical services to out of network payers, we should append the AS modifier to the charges with the rendering provider NPI being that of the surgeon, because the mid-level would not be in the payers system.

For our in-network surgical claims, we use the AS modifier & the mid-level rendering NPI.

Can someone please give me clarification on this? Any additional documentation you could provide, would be greatly appreciated!!!

Thanks in advance!

Last edited:
- AS Modifer

According to Medicare whenever a surgical assistant services are provided by a PA, NP or CNS, we are to use the-AS modifier in place of the -80. The SA modifier is used by Medi-Cal or Medicaid. So for any insurance that followes Medicare/private insurance use the -AS modifier. If they follow Medicaid/Medi-cal guidelines use the - SA.

Hope that helps