Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William Cash Byer, CRNA

Certified Registered Nurse Anesthetist in Bar Harbor, ME · enumerated 2011.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1285921403

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name William Cash Byer

Credential CRNA

Sex Male

Practice address 10 Wayman Ln, Bar Harbor, ME, 04609

Phone (207) 288-5081

Enumeration date Jul 8, 2011

Last updated in NPPES Sep 28, 2020

Taxonomy & licenses

367500000X Certified Registered Nurse Anesthetist Physician Assistants & Advanced Practice Nursing Providers · License 9242790 (FL) Secondary

367500000X Certified Registered Nurse Anesthetist Physician Assistants & Advanced Practice Nursing Providers · License 143046 (CT) Secondary

367500000X Certified Registered Nurse Anesthetist Physician Assistants & Advanced Practice Nursing Providers · License RNA203039 (ME) Primary

CRNA · Certified Registered Nurse Anesthetist: An advanced practice nurse specializing in anesthesia care. About the CRNA credential

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Is NPI 1285921403 active?

Yes, as of the latest NPPES snapshot, NPI 1285921403 is active (record last updated 2020-09-28).

How do I verify William Byer's NPI record?

Cross-check NPI 1285921403 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Other providers at this practice address

Browse all →

Robert Weiss Internal Medicine Physician · Bar Harbor, ME NPI 1538150503 Jorge Peacher Urogynecology and Reconstructive Pelvic Surgery (Obstetrics & Gynecology) Physician · Bar Harbor, ME NPI 1629052253 Maureen Magut Charette Diagnostic Radiology Physician · Bar Harbor, ME NPI 1205812476 John Benson Diagnostic Radiology Physician · Bar Harbor, ME NPI 1154308948 David Mcquade Diagnostic Radiology Physician · Bar Harbor, ME NPI 1497732283 Hancock County Radiology Consultants PA Diagnostic Radiology Physician · Bar Harbor, ME NPI 1831176627 Mount Desert Island Hospital Critical Access Hospital · Bar Harbor, ME NPI 1790764512 Mark Brown Internal Medicine Physician · Bar Harbor, ME NPI 1982683496

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2020-09-28.