CPT Code 00400 — What It Means on Your Medical Bill
CPT code · Anesthesia · Typically billed in: Hospital or surgery center
Seeing CPT code 00400 on your medical bill?
This code is only one part of the picture — your bill, EOB, insurance adjustments, units, and other charges may affect what you actually owe. MD Bill Check reads the codes on your document, checks the bill in context, and flags items that may be worth reviewing.
Codes normally billed as one with CPT code 00400
Medicare's National Correct Coding Initiative (NCCI) publishes pairs of codes that are considered a single service when performed together. Billing them separately — "unbundling" — inflates a bill.
| Paired code | How the pair is normally treated |
|---|---|
| 11406 Procedure | Not separately payable — the pair is expected to be billed as one service |
| 11606 Surgery | Not separately payable — the pair is expected to be billed as one service |
| 19081 Procedure | Not separately payable — the pair is expected to be billed as one service |
| 19120 Surgery | Not separately payable — the pair is expected to be billed as one service |
| 93000 Cardiac test | Separately payable only when a modifier documents a genuinely distinct service |
| 93005 Cardiac test | Separately payable only when a modifier documents a genuinely distinct service |
| 93306 Imaging | Separately payable only when a modifier documents a genuinely distinct service |
| 93970 Imaging | Separately payable only when a modifier documents a genuinely distinct service |
These are 8 of 47 pairs recorded for CPT code 00400. Seeing one of these codes billed alongside CPT code 00400 is not proof of an error — a modifier can legitimately justify it — but it is a specific, answerable question to put to the billing office. What unbundling means, and how to raise it.
Related codes
Keep reviewing your bill
- How to Check a Medical Bill for Errors Before You Pay
- Medical Bill vs EOB: What Is the Difference?
- What Is an Itemized Medical Bill? How to Request One
- Denial and remark codes explained (CARC & RARC)
Frequently asked questions about CPT code 00400
What does CPT code 00400 mean on a medical bill?
Anesthesia for skin procedures on the trunk or limbs. Bills group it under "Anesthesia", and it is typically provided in this setting: Hospital or surgery center.
Is CPT code 00400 normally billed together with other codes?
Medicare's National Correct Coding Initiative flags 47 codes that are normally billed as one service with CPT code 00400. If both appear as separate charges on your bill, it is worth asking the provider why they were billed separately.
Not sure this charge belongs on your bill?
Upload the bill — MD Bill Check reads the codes on your document, checks the bill in context, and flags items that may be worth reviewing. Free, no account needed.