Anesthesia is one of the clearest cases the No Surprises Act was written for. The patient chose the surgeon and the facility, not the anesthesiologist, and the law reflects that: anesthesiology is an “ancillary service,” so patients can’t be asked to waive their protections for it. Out-of-network anesthesia at an in-network hospital, hospital outpatient department, critical access hospital or ambulatory surgery center is protected, and payment disputes go to open negotiation and independent dispute resolution (IDR).
Why consent waivers don’t apply
For many non-emergency services, an out-of-network provider at an in-network facility can give the patient advance notice and ask them to consent to out-of-network billing. That route is closed for ancillary services, which include:
- anesthesiology,
- emergency medicine, radiology, pathology and neonatology,
- assistant surgeons, hospitalists and intensivists, and
- diagnostic services, including laboratory work.
The rule applies whether a physician or a non-physician practitioner provides the service, so CRNA services are covered too. For an anesthesia group, the practical upshot is that nearly every out-of-network case at an in-network facility is a payment dispute with the plan, not a bill to the patient.
How the QPA works for anesthesia
Anesthesia is paid on units, and the QPA follows suit. For services billed with base and time units, the plan calculates a median contracted conversion factor and applies it to the units for the case.
That gives you two separate things to check on every remit:
- The conversion factor — the rate per unit. This is the rate question, and it’s what IDR decides.
- The units — base units, time units and any modifying units. A miscounted unit is a coding error, and it’s fixed by appeal or corrected claim, not in IDR.
Read more on what the QPA is and how it’s built.
Where anesthesia underpayments come from
| Cause | Where to fix it |
|---|---|
| Conversion factor at or near the plan’s median | Open negotiation, then IDR |
| Time units truncated or rounded down | Plan appeal or corrected claim |
| Medical direction or supervision modifiers misapplied, triggering a reduction | Plan appeal or corrected claim |
| Physical status or qualifying-circumstance modifiers ignored | Plan appeal, and evidence for the IDR offer |
| Claim processed as if the facility were out of network | Confirm facility status, then dispute |
Sort each underpayment into the right bucket before acting. Taking a unit-count error to IDR wastes the dispute. See how to handle out-of-network underpayments.
Building the IDR offer
Anesthesia has strong evidence for the factors the IDR entity must weigh alongside the QPA:
- Patient acuity — physical status classification and emergency qualifying circumstances.
- Case complexity — the procedure, the patient’s comorbidities, the monitoring required.
- Training and experience — board certification and the care team model.
- Market share and contracting history — including any good-faith attempts to contract with the payer.
The IDR entity may not consider billed charges or Medicare rates, so offers built on either won’t carry weight.
Volume and batching
Anesthesia groups generate a steady flow of similar claims from the same payers. Batching qualifying claims makes disputes practical at that volume, and tracking awarded conversion factors by payer tells you what a fair rate looks like in your market — useful well beyond any single dispute. Keep an eye on the federal IDR timeline: at anesthesia volume, deadlines are the main risk.
This guide is general information, not legal advice. Confirm current requirements at cms.gov/nosurprises.