Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Mr. Gregory J. Callahan, BOCO

Other Technician in Baltimore, MD · enumerated 2007.

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

National Provider Identifier

1497944946

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Mr. Gregory J. Callahan

Credential BOCO

Sex Male

Practice address 3900 Loch Raven Blvd, Baltimore, MD, 21218

Phone (410) 605-7000

Fax (410) 605-7677

Enumeration date Oct 22, 2007

Last updated in NPPES Oct 22, 2007

Taxonomy & licenses

247200000X Other Technician Technologists, Technicians & Other Technical Service Providers · License C21679 (MD) Primary

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 Gregory Callahan's NPI record?

Cross-check NPI 1497944946 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1497944946 active?

Yes, as of the latest NPPES snapshot, NPI 1497944946 is active (record last updated 2007-10-22).

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-10-22.