Specialty billing
Anesthesia Medical Billing Services
Anesthesia billing uses a payment formula unlike any other specialty: base units for the procedure plus time units plus modifying units, multiplied by a conversion factor. Medical direction modifiers describing the supervising relationship determine what share of the fee each provider receives, and errors there are systematic rather than occasional.
Anesthesia benchmarks
- Typical denial rate
- 10–16%
- Days in AR
- 35–48
- Achievable clean claim rate
- 96%+
Typical ranges for anesthesia groups. Your actual numbers are measured during the audit.
The complexity
Why anesthesia is uniquely difficult to bill
Payment calculated as base units plus time units plus modifiers, times a conversion factor
Anesthesia time must be documented continuously from start to end of care
Medical direction modifiers determine fee split between anesthesiologist and CRNA
Concurrency rules limit how many cases an anesthesiologist may medically direct
The correct base unit depends on the anesthesia code, not the surgical code
Qualifying circumstances and physical status modifiers add units many groups never bill
Coding
Anesthesia procedure codes we work with daily
A representative sample, not an exhaustive list. Coders are assigned by specialty rather than pooled.
| Code | Description |
|---|---|
| 00790 | Anesthesia for intraperitoneal procedures in upper abdomen |
| 01402 | Anesthesia for total knee arthroplasty |
| 00840 | Anesthesia for intraperitoneal procedures in lower abdomen |
| 01967 | Neuraxial labor analgesia for planned vaginal delivery |
| 99100 | Qualifying circumstance: patient under 1 year or over 70 |
| 99140 | Qualifying circumstance: emergency condition |
Revenue leakage
Where anesthesia practices lose money
These are the denial patterns specific to this specialty — the ones a general-purpose billing service will not be looking for.
Medical direction modifier errors
Wrong modifier among AA, QK, QX, QY and QZ applied, causing incorrect fee splits or outright denial of one provider's claim.
Time documentation gaps
Anesthesia start and end times missing or inconsistent between the record and the claim, invalidating time units.
Concurrency violations
Medical direction billed on more cases than the concurrency rules permit for a single anesthesiologist.
Incorrect base units
Anesthesia code cross-walked from the surgical code incorrectly, assigning the wrong base unit value.
Unbilled qualifying circumstances
Physical status and qualifying circumstance modifiers omitted, forfeiting units the case legitimately supports.
Payer landscape
What anesthesia groups need to know about payers
Payer policy drives more anesthesia denials than coding does. Knowing the policy before the service is what prevents them.
- Conversion factors vary substantially by payer and geography, making payer-level reconciliation essential to detect underpayment.
- Medicare applies specific medical direction rules; several commercial payers apply their own variants that differ in fee split.
- Labor epidural billing conventions differ widely — some payers pay by time, others by a flat allowance.
Questions
Anesthesia billing FAQ
Last updated August 20, 2026
Reviewed by a certified coding leadTotal units equal base units for the anesthesia code, plus time units (typically one per 15 minutes), plus any modifying units for physical status and qualifying circumstances. That total is multiplied by the payer's conversion factor. Because the formula is multiplicative, a single missing unit type reduces every affected claim proportionally.
AA indicates the anesthesiologist personally performed the case. QK indicates medical direction of two to four concurrent cases. QX is the CRNA's claim under medical direction, QZ is a CRNA without medical direction, and QY is direction of a single CRNA. The pairing must be consistent across both providers' claims or one will deny.
Because physical status modifiers and qualifying circumstance codes for extreme age or emergency conditions are documented clinically but not carried through to the claim. These units are legitimately earned on a meaningful share of cases and are among the most commonly forfeited revenue in the specialty.
We track case overlap by anesthesiologist and date to confirm medical direction claims stay within the permitted concurrency limits. Exceeding them is both a denial risk and a compliance exposure, and it is difficult to detect without systematic case-level review.
Primary sources
Coverage, rates and local policy for anesthesia, at the source.
- Medicare Physician Fee Schedule lookup (opens in a new tab)
Centers for Medicare & Medicaid Services — Official allowed amounts by CPT/HCPCS code and locality. The reference point most commercial contracts are written against as a percentage.
- Medicare Claims Processing Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — The operative manual for how Medicare claims must be coded, submitted, adjusted and appealed. When a payer policy and a vendor's advice disagree, this settles it.
- Medicare Coverage Database (LCD/NCD) (opens in a new tab)
Centers for Medicare & Medicaid Services — Searchable national and local coverage determinations. The direct answer to whether a diagnosis supports medical necessity for a given procedure.
Get a free anesthesia billing audit
We'll review your anesthesia denial patterns, coding accuracy and AR aging against the benchmarks above. Takes about two minutes to request.
No setup fees · You pay when we collect · Pricing from 3% of net collections