WILLIAM CASH BYER CRNA
NPI 1285921403
Nurse Anesthetist, Certified Registered in Bar Harbor, ME
About William Cash Byer Crna NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
WILLIAM CASH BYER CRNA (NPI 1285921403) is an individual nurse anesthetist, certified registered in Bar Harbor, Maine, licensed in Maine (RNA203039) and active in the NPI registry since July 2011. He is enrolled in Medicare PECOS, is affiliated with Mount Desert Island Hospital, and is a graduate of Other (2011).
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
William Cash Byer Crna is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
7Medicare enrollment records show William Byer reassigns Medicare billing to 7 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Bar Harbor, ME 04609
- Reassigned Medicare billing, Maine enrollment
- 87 clinicians in this Medicare group
Machias, ME 04654
- Reassigned Medicare billing, Maine enrollment
- 34 clinicians in this Medicare group
Calais, ME 04619
- Reassigned Medicare billing, Maine enrollment
- 43 clinicians in this Medicare group
Manchester, ME 04351
- Reassigned Medicare billing, Maine enrollment
- 920 clinicians in this Medicare group
Rumford, ME 04276
- Reassigned Medicare billing, Maine enrollment
- 544 clinicians in this Medicare group
Hamden, CT 06514
- Reassigned Medicare billing, Connecticut enrollment
- 3,728 clinicians in this Medicare group
Las Cruces, NM 88011
- Reassigned Medicare billing, New Mexico enrollment
- 238 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mount Desert Island Hospital
Critical Access Hospitals · Bar Harbor, MEMountain View Regional Medical Center
Acute Care Hospitals · Las Cruces, NMPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 04609 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is William Byer's NPI number?
The NPI number for William Byer is 1285921403. It was assigned to this individual provider in the NPPES registry on July 8, 2011.
Where is William Byer located?
William Byer practices at 10 Wayman Ln, Bar Harbor, ME 04609. The listed phone number is (207) 288-5081.
What is William Byer's specialty?
The primary specialty registered for this NPI is Nurse Anesthetist, Certified Registered with taxonomy code 367500000X.
Is William Byer enrolled in Medicare?
Yes. William Byer is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for William Byer's services?
According to the CMS Revalidation Reassignment List (October 2026 release), William Byer reassigns Medicare benefits to 7 organizations: Mount Desert Island Hospital (Bar Harbor, ME), Down East Community Hospital (Machias, ME), Calais Community Hospital (Calais, ME), Central Maine Medical Center (Manchester, ME), Rumford Hospital (Rumford, ME) and 2 more organizations, listed in the Medicare section above. Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for William Byer's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is William Byer affiliated with any hospitals?
According to CMS data, William Byer is affiliated with Mount Desert Island Hospital and Mountain View Regional Medical Center.
When was this NPI record last updated?
The NPPES record for William Byer was last updated on September 28, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# William Cash Byer, CRNA · NPI 1285921403
Nurse Anesthetist, Certified Registered physician in Bar Harbor, Maine. Individual provider, active in the CMS NPPES registry since July 8, 2011.
## Identity
- **NPI:** 1285921403 (Entity type: Individual)
- **Enumerated:** July 8, 2011
- **Primary specialty:** Nurse Anesthetist, Certified Registered · taxonomy 367500000X
- **State license:** RNA203039 (Maine)
- **Sole proprietor:** No
## Practice location
- **Address:** 10 WAYMAN LN, Bar Harbor, ME 04609-1625
- **Phone:** (207) 288-5081
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging
- **Bills Medicare through:** 7 organizations under Medicare reassignment (form CMS-855R): Mount Desert Island Hospital (NPI 1790764512, Bar Harbor, ME); Down East Community Hospital (NPI 1700883139, Machias, ME); Calais Community Hospital (NPI 1922001049, Calais, ME); Central Maine Medical Center (NPI 1598411175, Manchester, ME); Rumford Hospital (NPI 1205991122, Rumford, ME); and 2 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2011
## Record status
- **NPPES last updated:** September 28, 2020
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Source: [NPI Profile](https://npiprofile.com/npi/1285921403) · Data from the CMS NPPES public registry.