Access CMS anesthesiology resources, including Medicare payment policies, anesthesia conversion factors, billing guidance, and participation requirements.
Anesthesia conversion factors used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999
| Anesthesia Conversion Factors Files | Notes | Update Date |
|---|---|---|
| 2026 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2026 | 12/29/2025 |
| 2025 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2025 | 12/26/2024 |
| 2024 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2024 | 03/14/2024 |
| 2023 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2023 | 01/06/2023 |
| 2022 Anesthesia Conversion Factors (ZIP) | 12/20/2021 | |
| 2022 Anesthesia base units by CPT code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2021 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2021 | 12/29/2020 |
| 2020 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2020 | |
| 2019 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for CY 2019 | |
| 2018 Anesthesia Conversion Factors (ZIP) | ||
| 2018 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2017 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for 2017 | |
| 2016 Anesthesia Conversion Factors (ZIP) | The anesthesia base units are unchanged for 2016 | |
| 2015 Anesthesia Conversion Factors (July 1- Dec 31) (ZIP) | The anesthesia base units are unchanged for 2015 | |
| 2015 Anesthesia Conversion Factors (Jan 1 – June 30) (ZIP) | The anesthesia base units are unchanged for 2015 | 01/06/2015 |
| 2014 Anesthesia Conversion Factors (ZIP) | 01/03/2014 | |
| 2014 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2013 Anesthesia Conversion Factors (ZIP) | 12/31/2012 | |
| 2013 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2012 Anesthesia Conversion Factor 0% Update (ZIP) | 03/01/2012 | |
| 2012 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2011 Anesthesia Conversion Factor (ZIP) | 04/02/2012 | |
| 2011 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2010 Anesthesia Conversion Factor 0% update and 2010 Anesthesia Conversion Factor 2.2% update | ||
| 2010 Anesthesia Base Units by CPT Code (ZIP) | These are the anesthesia base units used to compute allowable amounts for anesthesia services under CPT codes 00100 to 01999 | |
| 2009 Anesthesia Conversion Factor (ZIP) |
