Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William Alexander Calder, MD

Family Medicine Physician in Arapahoe, WY · enumerated 2006.

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

National Provider Identifier

1275605412

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name William Alexander Calder

Credential MD

Sex Male

Practice address 14 Great Plains Rd, Arapahoe, WY, 82510

Phone (307) 856-9281

Enumeration date Nov 14, 2006

Last updated in NPPES Nov 17, 2011

Taxonomy & licenses

207Q00000X Family Medicine Physician Allopathic & Osteopathic Physicians · License 4066A (WY) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD 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

How do I verify William Calder's NPI record?

Cross-check NPI 1275605412 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1275605412 active?

Yes, as of the latest NPPES snapshot, NPI 1275605412 is active (record last updated 2011-11-17).

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-11-17.