CPT 00400: Anesthesia, skin/tissue
What this code means, what it should cost, and how to dispute an overcharge.
Fair Price Reference
What is CPT 00400?
CPT 00400 (Anesthesia, skin/tissue) is a anesthesia billing code defined by the American Medical Association. It's used to bill your insurance or you directly for this service.
What CPT 00400 should cost
The Centers for Medicare & Medicaid Services (CMS) pays approximately $190 for CPT 00400 under the 2025 Physician Fee Schedule. This is what the federal government has determined is a reasonable payment for this service.
Private insurance typically pays 1.2–1.8x Medicare rates ($228–$342). Hospital chargemaster prices for CPT 00400 often range from $350 to $1500 — a markup of 1.8x to 7.9x over Medicare.
Common overcharges on CPT 00400
Inflated time units. Billing the physician anesthesiologist AND the CRNA for the same case at full rate (should be medical direction at partial rate). Balance billing by out-of-network anesthesiologists (prohibited by the No Surprises Act).
About Anesthesia billing
Anesthesia is billed by time units — and time units are the most commonly inflated component of anesthesia charges.
Request the anesthesia record — it documents actual start/stop times. Verify billed units match documented time. Out-of-network anesthesia billing is illegal under the No Surprises Act.
How to dispute a CPT 00400 overcharge
- Request the itemized bill. You are entitled to a detailed line-by-line bill showing every CPT code billed. Ask in writing.
- Compare to Medicare allowable. If the charge exceeds 150% of Medicare ($285), you have grounds to dispute.
- Request documentation. For E&M codes, ask for the visit note. For procedures, ask for the operative report. The documentation must justify the code billed.
- Send a formal dispute letter. Cite the specific discrepancy between the documentation and the code. Reference Medicare rates and NCCI edits where applicable.
- Follow up in writing. Give the provider 30 days to respond. If they don't, escalate to the state attorney general and insurance commissioner.
Got CPT 00400 on your bill?
Upload your bill. We scan every line for overcharges, upcoding, and improper unbundling — then generate a dispute letter backed by federal law. Free for uninsured and veterans.