Anesthesia Care Team Ratios: What 1:2, 1:3 and 1:4 Really Cost
By Andrew Woodmancey, Managing Director · Published
The short answer: at today’s pay, a care team only costs less than anesthesiologists working alone when each anesthesiologist directs three or more rooms. With median posted pay of $550,000 for anesthesiologists and $300,000 for CRNAs (September 2026), a room staffed at 1:2 costs about 5% more than a room covered by an anesthesiologist alone; at 1:3 it costs about 12% less, and at 1:4 about 20% less. Under Medicare’s rules the case pays the same total either way, because under medical direction the anesthesiologist and the CRNA each receive half the fee. So the ratio changes what coverage costs, not what it collects. The ratio a schedule actually runs is often lower than the one on paper.
The break-even rule
One anesthesiologist directing N rooms puts a CRNA in every room and 1/N of an anesthesiologist on top. That beats an anesthesiologist in every room only when:
CRNA cost < anesthesiologist cost × (1 − 1/N)
- 1:2 needs a CRNA to cost less than half of an anesthesiologist.
- 1:3 needs less than two thirds.
- 1:4 needs less than three quarters.
Nationally, the median posted CRNA salary is about 55% of the median anesthesiologist salary, so 1:2 misses the line and 1:3 and 1:4 clear it. The figures below apply the same pay to both models, with 20% added for benefits, taxes and malpractice, 220 shifts a year per full-time clinician, 10% extra for call, breaks and relief, and rooms running 250 days a year.
Pay: national medians of posted annual pay, September 2026, from our job-posting index. Each room needs 1.25 full-time clinicians a year at these assumptions.
The answer depends on your state
The national ratio hides wide local differences, because CRNA pay varies far more by state than anesthesiologist pay. In the states with at least 30 postings stating pay for both professions:
| State | Median anesthesiologist | Median CRNA | CRNA as share of anesthesiologist | Lowest ratio that costs less than anesthesiologists only |
|---|---|---|---|---|
| Pennsylvania | $525,000 | $387,500 | 74% | 1:4, barely |
| California | $600,000 | $400,000 | 67% | 1:4 (1:3 breaks even) |
| North Carolina | $525,000 | $300,000 | 57% | 1:3 |
| Illinois | $550,000 | $300,000 | 55% | 1:3 |
| Texas | $600,000 | $320,000 | 53% | 1:3 |
| New York | $600,000 | $310,000 | 52% | 1:3 |
| Virginia | $525,000 | $265,000 | 50% | 1:3 (1:2 about breaks even) |
| Florida | $550,000 | $270,000 | 49% | 1:2, narrowly |
State medians cover the three months to September 2026. In Pennsylvania a CRNA is advertised at nearly three quarters of an anesthesiologist’s pay, so even 1:3 costs more than anesthesiologists alone; in Florida a 1:2 team is just below break-even. A care team ratio chosen years ago, when the relative pay was different, may no longer be the cheapest way to cover the same rooms.
The ratio on paper and the ratio the schedule runs
Anesthesiologists come in whole numbers. A department planning 1:4 with six rooms still needs two directing anesthesiologists, which is 1:3. Five rooms at 1:4 is 1:2.5. The calculator default of six rooms shows it: the 1:3 and 1:4 models cost exactly the same.
| Rooms running | Planned 1:2 | Planned 1:3 | Planned 1:4 |
|---|---|---|---|
| 3 | 2 anesthesiologists (1:1.5) | 1 (1:3) | 1 (1:3) |
| 4 | 2 (1:2) | 2 (1:2) | 1 (1:4) |
| 5 | 3 (1:1.7) | 2 (1:2.5) | 2 (1:2.5) |
| 6 | 3 (1:2) | 2 (1:3) | 2 (1:3) |
| 7 | 4 (1:1.75) | 3 (1:2.3) | 2 (1:3.5) |
| 8 | 4 (1:2) | 3 (1:2.7) | 2 (1:4) |
The schedule pulls the ratio down further. To bill medical direction, the anesthesiologist has to be personally present for induction and emergence, where they apply, in every directed room and may never direct more than four cases at once, counting every payer (the seven steps). Four rooms that all start at 7:30 cannot all be inducted by one person, so first cases are often staggered or covered with extra anesthesiologists. An anesthesiologist who personally performs a case while directing others is performing other services, and the directed cases become medical supervision (modifier AD) for the whole case, which pays the anesthesiologist less on most cases (not on short, low-unit cases such as many endoscopies). Breaks, lunch relief and late rooms add more. When a group quotes a ratio, ask for the ratio it actually ran, by day and by room.
Research bears this out. A study of a year of operating room records at one tertiary hospital (Epstein and Dexter, Anesthesiology, 2012) found that, staffing the whole suite at 1:2, anesthesiologists would have been unable to be present for every critical portion of every case on 35% of days; at 1:3, on 99% of days. When the early-morning starts were excluded, modeling staggered starts or extra anesthesiologists at the start of the day, the 1:3 figure fell to 14% of days, but rose to 62% once breaks, mainly lunch relief, were counted. At 1:2 it fell to 0% and 2%.
What the ratio does to the subsidy
Collections do not change with the ratio under Medicare’s rules (the calculator applies the same split to every payer; commercial contracts can differ), so every dollar of staffing cost lands in the gap the hospital is asked to cover. With the subsidy calculator’s default inputs — six rooms, four cases per room per day, 12 units per case, a 35% Medicare, 15% Medicaid, 45% commercial and 5% self-pay mix, and a $75 commercial conversion factor — the coverage collects about $3.0 million a year, and the gap is:
| Model (six rooms) | Staffing cost | Gap for the hospital | Per room |
|---|---|---|---|
| Anesthesiologists only | $4.95M | $1.93M | $322,000 |
| Care team 1:2 | $5.18M | $2.16M | $360,000 |
| Care team 1:3 or 1:4 (two anesthesiologists either way) | $4.35M | $1.33M | $222,000 |
| CRNAs only | $2.70M | $0.18M surplus | — |
CRNA-only coverage collects a little less than the others, about $2.9 million, because several commercial payers now pay CRNA claims billed without medical direction (QZ) at 85% (the 85% rule), and the calculator assumes 40% of commercial volume is affected. It is still far cheaper to staff, which is why it comes out ahead on cost. Whether it is allowed is a separate question: where a state has not opted out of Medicare’s supervision requirement, the CRNA must be supervised by the operating practitioner or by an anesthesiologist who is immediately available (the opt-out list), state law and hospital bylaws may require more, and the model leaves no anesthesiologist on site for complex cases.
When the more expensive ratio is still the right one
- Case mix. Cardiac, pediatric, trauma and other high-acuity rooms often need an anesthesiologist present more continuously than a 1:4 ratio allows.
- Outcomes. A study of adult inpatient surgery at 23 hospitals (Burns and colleagues, JAMA Surgery, 2022) found risk-adjusted 30-day complications and deaths in 5.75% of cases when the anesthesiologist was covering more than three and up to four overlapping operations, against 5.06% when covering more than one and up to two: a modest but measurable difference. The American Society of Anesthesiologists sets no maximum ratio but cautions against assigning one physician a high number of sites.
- Obstetrics and call. Labor epidurals, nights and weekends are covered by whoever is in house, and those hours rarely run at the daytime ratio.
- Recruiting. A ratio is only cheaper if the CRNAs can be hired. Among CRNA postings in our index that say how they pay, hourly and locums openings outnumber salaried ones about six to one, and a schedule that depends on that market pays its rates.
- Billing discipline. A care team that cannot document the seven steps loses medical direction on those cases. Depending on what went wrong and on the Medicare contractor, they are paid at the lower supervision rate or not at all, which erases much of the savings and creates repayment exposure.
Questions to ask your anesthesia group
- What ratio did you actually run last quarter, by day of week and by location?
- What share of cases was billed as medical direction (QK or QY), personally performed (AA), supervision (AD) and CRNA without direction (QZ)?
- How are first-case starts staggered so each induction has an anesthesiologist present?
- How many anesthesiologists are doing cases themselves while also directing, and for how long?
- Would a different ratio at some locations lower the cost of the same coverage?
Each answer moves the subsidy. To test your own numbers, the anesthesia subsidy calculator shows staffing cost, collections and the gap for anesthesiologist-only, 1:2, 1:3, 1:4 and CRNA-only coverage side by side.
Sources
- 42 CFR 415.110, conditions for payment: medically directed anesthesia services.
- 42 CFR 414.46, payment for anesthesiology services.
- CMS, Medicare Claims Processing Manual, chapter 12, section 50.
- Epstein RH, Dexter F. Influence of supervision ratios by anesthesiologists on first-case starts and critical portions of anesthetics. Anesthesiology 2012;116:683–91.
- Burns ML, et al. Association of anesthesiologist staffing ratio with surgical patient morbidity and mortality. JAMA Surgery 2022;157(9):807–815.
- American Society of Anesthesiologists, Statement on the Anesthesia Care Team (amended October 2023).
- AOC job-posting index: Anesthesiologist and CRNA Pay in 2026, September 2026 national and state medians from publicly posted anesthesia job listings from national job boards.