CMS has proposed cutting the Medicare anesthesia conversion factor 1.38% in 2027, to $20.2143 from $20.4976, according to the American Society of Anesthesiologists. For anesthesia providers in qualifying alternative payment models, the rate would fall 0.89%, to $20.4165 from $20.5998.
The drop mainly reflects the expiration of the 2.5% payment increase Congress authorized for 2026, ASA said. It is partly offset by a 0.25% statutory update for most physicians and a 0.75% update for qualifying APM participants.
Medicare pays anesthesia by adding procedure base units to one time unit per 15 minutes, then multiplying by the conversion factor. Here is how the proposed rate changes national payment for four common ASC cases, using example anesthesia times:
| Anesthesia code | Units (example time) | 2026 payment | 2027 proposed | Change per case |
| Lumbar spine fusion (00670) | 25 (180 min) | $512.44 | $505.36 | -$7.08 |
| Total knee replacement (01402) | 15 (120 min) | $307.46 | $303.21 | -$4.25 |
| Colonoscopy (00811) | 6 (30 min) | $122.99 | $121.29 | -$1.70 |
| Cataract surgery (00142) | 5 (15 min) | $102.49 | $101.07 | -$1.42 |
The cut applies to the full allowance whether an anesthesiologist or a certified registered nurse anesthetist works alone. Under medical direction, each provider’s 50% share falls by half these amounts.
In its September comments, ASA said the update “falls far short of keeping pace with rising practice costs, workforce expenses, and inflation.”
The cut comes as many ASCs already subsidize anesthesia coverage: 31% offer financial assistance in anesthesia contracts, about the same as in 2024, according to a third-quarter survey from the Ambulatory Surgery Center Association.
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