Anesthesiologist Assistant: how many are there, and how many are in private practice?

National totals

What this specialty covers

An individual certified by the state to perform anesthesia services under the direct supervision of an anesthesiologist. Anesthesiologist Assistants are required to have a bachelor's degree with a premed curriculum prior to entering a two-year anesthesiology assistant program, which is focused upon the delivery and maintenance of anesthesia care as well as advanced patient monitoring techniques. An Anesthesiologist Assistant must work as a member of the anesthesia care team under the direction of a qualified Anesthesiologist.

Reading the sole-proprietor share

For this specialty, the sole-proprietor share describes how records are marked in NPPES, not whether an Anesthesiologist Assistant works independently. Because these clinicians must work as members of an anesthesia care team under a qualified anesthesiologist, practice arrangements may not fit a sole-proprietor label. The field is self-reported and can be incomplete or outdated, so it is an imperfect proxy for private practice or ownership.

By state

New NPI registrations by year

Counts reflect the year each NPI was first issued, among records still active today. The final year is partial: this data covers through 2026-01-11.

Data notes

• The sole-proprietor field is self-reported by the provider in NPPES and is an imperfect proxy for private practice.
• A sole-proprietor count shown as <11 is suppressed: the true value is below 11, which could include zero.
• - NPI counts are records and may not equal the number of unique actively practicing people.
• - The year an NPI was first enumerated does not establish when training, employment, or clinical practice began.
• Providers are counted once, by their primary taxonomy code only.

Source: CMS National Plan and Provider Enumeration System (NPPES) Data Dissemination file, FOIA-disclosable public data under CMS-6060-N. Aggregated by Hero EMR on 2026-08-03; deactivated NPIs excluded; specialty assigned from the primary taxonomy code (NUCC 25.1). Counts below 11 are suppressed. Individual providers are never published. All provider data pages.

Common questions