Dr. William C O'Callahan Jr., MD
Emergency Medicine in Holden, Massachusetts
1114964186- Practice location
- 5 Shrewsbury St Ste D, Holden, MA 01520-1960
- Phone
- 508-829-3800
- Fax
- 508-829-3802
- Last updated
- October 4, 2026
William Charles O'Callahan is an Emergency Medicine based in Holden, MA. William Charles O'Callahan practices in Holden, MA and has the professional credentials of MD. The NPI Number for William Charles O'Callahan is 1114964186 and holds a License No. 79001 (MA). The current practice location address for William Charles O'Callahan is 5 Shrewsbury St Ste D, Holden, MA 01520-1960 and can be reached out via phone at 508-829-3800 and via fax at 508-829-3802.
Provider Profile Details
- NPI Number
- 1114964186
- Provider Name
- William Charles O'Callahan
- Credential
- MD
- Provider Entity Type
- Individual
- Gender
- Male
- Address
- 5 Shrewsbury St Ste D, Holden, MA 01520-1960
- Phone Number
- 508-829-3800
- Fax Number
- 508-829-3802
- Primary Taxonomy
- Emergency Medicine · 207P00000X
- Sole Proprietor
- No
- Provider Enumeration Date
- May 31, 2006
- Last Update Date
- October 4, 2026
- Certification Date
- October 4, 2026
- NPI Status
- Active
Provider Business Practice Location Address Details
- Address
- 5 Shrewsbury St Ste D
Holden, MA 01520-1960 - City
- Holden
- State
- Massachusetts
- Zip
- 01520-1960
- Phone Number
- 508-829-3800
- Fax Number
- 508-829-3802
Provider Business Mailing Address Details
- Address
- 5 Shrewsbury St Ste D
Holden, MA 01520-1960 - City
- Holden
- State
- MA
- Zip
- 01520-1960
- Phone Number
- 508-829-3810
- Fax Number
- 508-829-3815
License Information
- License Number
- 79001
- License State
- MA
- Taxonomy
- Emergency Medicine · 207P00000X · Primary
Legacy Identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| No legacy identifiers (Medicaid, Medicare or plan IDs) are on file for this provider. | |||
Other Emergency Medicine providers near Holden, MA
View all Emergency Medicine providers in Holden →Frequently Asked Questions
What is the NPI number of Dr. William C O'Callahan Jr., MD?
The NPI number of Dr. William C O'Callahan Jr., MD is 1114964186. It was assigned on May 31, 2006 and is currently active in the NPPES registry.
What is the specialty of Dr. William C O'Callahan Jr., MD?
Dr. William C O'Callahan Jr., MD is registered under the primary taxonomy Emergency Medicine (code 207P00000X), licensed in MA under license number 79001.
Where does Dr. William C O'Callahan Jr., MD practice?
The practice location is 5 Shrewsbury St Ste D, Holden, MA 01520-1960. The office can be reached at 508-829-3800 (phone) or 508-829-3802 (fax).
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit identification number issued to health care providers in the United States by the Centers for Medicare and Medicaid Services (CMS). It is used in HIPAA standard transactions.
How do I verify this NPI record?
This record is sourced from the public NPPES NPI Registry maintained by CMS. You can confirm it by searching NPI 1114964186 directly on the NPPES registry website.