Anesthesia Billing Services
Anesthesia billing is fundamentally different from every other medical specialty. Instead of CPT codes with fixed reimbursement rates, anesthesia uses a base unit + time unit formula. The base units come from the ASA Relative Value Guide, the time units depend on how long the case runs, and the conversion factor varies by payer. A 3-hour spine case reimburses differently than a 45-minute knee scope, even if the anesthesia technique is identical. Most general billing companies don’t understand this system.
We bill for anesthesia groups covering hospitals, ambulatory surgery centers, and office-based procedures. We calculate time units from anesthesia start to anesthesia end (not surgery start to surgery end), apply the correct base units from the ASA crosswalk, and negotiate conversion factors with payers who try to underpay.
Anesthesia billing at a glance
Common anesthesia procedures we bill daily.
General Anesthesia
Regional Anesthesia
Monitored Anesthesia Care (MAC)
Anesthesia billing challenges we solve every day.
Anesthesia is one of the most complex specialties to bill. High-value procedures, strict documentation requirements, and frequent payer policy changes mean even experienced in-house billers miss revenue. For coding standards, see the American Society of Anesthesiologists.
Time unit calculation
Anesthesia time begins when the anesthesiologist starts preparing the patient and ends when care is transferred to post-anesthesia personnel. This is not the same as surgical start/end time. Each 15-minute increment equals one time unit (Medicare) though some commercial payers use different intervals. Rounding rules vary by payer. We capture anesthesia-specific times from the anesthesia record, not the surgical record.
Base unit disputes
Payers sometimes apply incorrect base units, particularly for complex cases or when multiple surgical procedures are performed during the same anesthetic. The ASA Relative Value Guide assigns base units by procedure, and when multiple procedures occur, only the procedure with the highest base unit value is reported (plus time units for the entire case). We verify base unit assignments against the ASA crosswalk for every claim.
Qualifying circumstances and physical status modifiers
Complex cases qualify for additional base units: extreme age (99100), controlled hypotension (99135), hypothermia (99116), or emergency conditions (99140). Physical status modifiers (P1-P6) indicate patient acuity but are not uniformly accepted by all payers. We apply qualifying circumstance codes and physical status modifiers where supported to maximize reimbursement.
Concurrent and medically directed cases
When an anesthesiologist medically directs CRNAs, the billing rules change. Medicare allows medical direction of up to 4 concurrent cases with specific presence and documentation requirements. The anesthesiologist bills with modifier QK/QY and the CRNA bills with modifier QX. Violating the concurrency rules means the anesthesiologist’s claims get reduced to medical supervision rates (modifier AD), which pay significantly less.
Full-service anesthesia billing across your revenue cycle.
Simple, transparent anesthesia billing pricing.
We also bill for these specialties.
Ready to fix your anesthesia billing?
Schedule a free consultation. We’ll review your current billing performance, identify where you’re losing revenue, and build a plan to get your anesthesia practice paid faster.
