Anesthesia Units Calculator

Enter base units, anesthesia time and a conversion factor to estimate anesthesia payment with the standard units formula.

How anesthesia billing differs

Anesthesia is the one specialty that doesn’t bill flat procedure rates: payment is built from units — base units set by the procedure’s complexity, plus time units accrued while the anesthesiologist is with the patient — multiplied by a dollar conversion factor. Enter the three components and this calculator returns the estimate, with the time-unit interval adjustable because payers differ on it.

How to use it

  1. Enter the base units for the procedure (from the anesthesia base-unit schedule your payer follows).
  2. Enter the anesthesia time in minutes.
  3. Set the minutes-per-time-unit (15 is the common standard) and the payer’s conversion factor.

The formula

payment = (base units + minutes ÷ interval) × conversion factor

A worked example

A 5-base-unit case running 75 minutes at 15-minute intervals accrues 5 time units — 10 total units — and at a $22 conversion factor pays $220. The same case at a commercial factor of $70 pays $700, which is the entire story of anesthesia payer mix in one comparison: the units are fixed by the case, the factor is fixed by the contract.

Estimates only — payer contracts, plan documents and the EOB are always the source of truth, and nothing here is billing, legal or medical advice. The calculator runs entirely in your browser: no patient data is entered, transmitted or stored.

Physical-status and qualifying-circumstance units, medical-direction splits and payer rounding rules all modify real payment — enter them into the base figure where applicable, and confirm against the payer’s policy.

Common questions

Where do base units come from?
Published base-unit schedules assign each anesthesia code a complexity value — your payer’s policy states which schedule it follows. They’re fixed per procedure regardless of duration.
How is anesthesia time counted?
From preparing the patient for induction until safe transfer of care — documented start and stop times, not scheduled OR time. Payers audit exactly this.
Do payers round time units differently?
Yes — exact decimals, rounding up, or whole-unit thresholds all exist. The calculator uses exact decimals; apply the payer’s rounding rule to match remits.