Procedure guidesBillSherpa · Updated 2026
Surgery Billing Errors — The Most Common Charges That Shouldn't Be There
Surgical billing is among the most complex in healthcare — multiple providers, multiple bill types, high dollar amounts, and documentation that spans pre-op, intra-op, and post-op phases. Patients are often in no condition to scrutinise their bills during recovery. That's exactly why surgical billing errors are so common and so costly.
The structure of a surgical bill
A typical surgery generates bills from at least four separate parties:
- The hospital or surgical center — facility fee covering the operating room, recovery room, nursing staff, equipment, and supplies
- The surgeon — professional fee for performing the operation
- The anesthesiologist — professional fee for anesthesia services
- The assistant surgeon — if one was present
For complex procedures, add: the pathologist (if tissue was sent for analysis), the radiologist (if intraoperative imaging was used), and any consulting specialists. Each bills separately, each has their own coding, and the opportunity for errors multiplies accordingly.
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The most common surgical billing errors
Unbundling — billing procedure components separately
NCCI Policy Manual
The NCCI (National Correct Coding Initiative) defines which procedure codes must be billed together. When a surgeon bills the primary procedure and then separately bills component steps that are already included in the primary code, that's unbundling — and it inflates your bill significantly. Common example: billing for a laparoscopic port insertion (CPT 49320) separately from the laparoscopic procedure it's part of.
Billing for the assistant surgeon when one isn't covered
CPT modifier -80, -81, -82
Not all procedures warrant an assistant surgeon under Medicare and insurer coverage policies. If you were billed for an assistant surgeon on a procedure where one isn't typically covered, that's a potential billing error. CMS publishes a list of procedures where assistant surgeons are and are not covered.
Anesthesia time billed incorrectly
Anesthesia CPT codes 00100–01999
Anesthesia is billed in time units (typically 15-minute increments) plus base units for the procedure. Compare the anesthesia time billed against your surgical records — the anesthesia start and stop times are documented. If the billed time exceeds the actual documented time, you're being overcharged.
Out-of-network anesthesiologist billing
No Surprises Act · 42 U.S.C. § 300gg-111
You chose your in-network surgeon and in-network hospital. You had no choice over which anesthesiologist was assigned. Under the No Surprises Act, if the anesthesiologist is out of network and you didn't sign a valid consent form acknowledging this for a genuinely voluntary service, they cannot balance-bill you above your in-network cost-sharing.
Post-operative visits billed separately during global period
Global surgical package rules
Most surgical CPT codes include a "global period" — 10 days for minor procedures, 90 days for major procedures — during which routine follow-up visits are included in the original surgical fee. Billing separately for a post-op visit during the global period is a billing violation. Check any follow-up visit charges within 90 days of a major surgery.
Surgical supply charges for unused items
Revenue codes 0270–0279
Surgical suites often open supplies "in case" they're needed. Items opened but not used are sometimes added to the patient's bill. Your medical records and the operating room nursing notes document what was actually used — supplies that don't appear in those notes shouldn't appear on your bill.
How to audit your surgical bill
- Request itemized bills from all providers. Get separate itemized bills from the hospital/surgical center, the surgeon, the anesthesiologist, and any other billed providers.
- Request the operative report. The operative report is the surgeon's documentation of exactly what was done. It's your primary comparison document for the surgical procedure codes billed.
- Request the anesthesia record. This documents anesthesia start time, stop time, agents used, and monitoring — all billable elements. Compare against the anesthesia bill.
- Request the nursing/scrub tech record. The intraoperative nursing record documents supplies used, equipment, and the surgical timeline. Compare against supply charges.
- Check for NCCI violations. Look up the primary surgical CPT code and the additional codes billed. BillSherpa's analysis covers NCCI bundling rules automatically.
- Verify the global period. Count 10 or 90 days from your surgery date. Any post-op visits with your surgeon during this window should not generate a separate bill.
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Surgery billing checklist
- Collect itemized bills from all providers — hospital, surgeon, anesthesiologist, others
- Request operative report, anesthesia record, and nursing notes
- Verify anesthesia time billed matches documented start and stop times
- Check for unbundled procedure codes using NCCI edits
- Confirm assistant surgeon billing is covered for this procedure type
- Check that anesthesiologist is not balance-billing above in-network rate (No Surprises Act)
- Verify no post-op visit charges during the global period (10 or 90 days)
- Check supply charges against intraoperative nursing documentation
Frequently asked questions
My surgeon is in-network but the anesthesiologist billed me out-of-network rates. Is this legal?
In most cases, no. If your surgery was at an in-network facility and the anesthesiologist was assigned to your case without your advance written consent to out-of-network billing, the No Surprises Act protects you. Your responsibility is capped at your in-network cost-sharing. Reference 42 U.S.C. § 300gg-111 in your dispute.
What is a "surgical tray" charge and should I be billed for it?
Surgical tray or instrument tray charges cover the specialized instruments used during a procedure. These are typically included in the surgical facility fee or the procedure code itself and should not be billed separately. If you see a separate "surgical tray" line item, verify it isn't already bundled into another code you've been charged for.
I had surgery three months ago and I'm still getting bills. Is this normal?
Unfortunately yes. Separate bills from different providers can arrive weeks or months after surgery as each billing department processes their claims. Keep all bills and match each against your EOBs. Don't pay anything until you have an EOB confirming what you actually owe for each provider.