IndividualActive
William Callahan, MD
NPI 1356344535 · Specialist · Gainesville, GA
William Callahan, MD is a Specialist provider in Gainesville, GA (NPI 1356344535).
Provider details
- NPI number
- 1356344535
- Entity type
- Individual
- Primary specialty
- SpecialistOther Service Providers
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 14469 (GA)
Specialties & taxonomies
Other Service Providers
Profile Score
Detailed profile(91/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
21 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
663 Lanier Park Dr
Gainesville, GA 30501
Phone: (770) 536-8109
Fax: (770) 536-3203
Street-level locationGet directions
Mailing address
663 Lanier Park Dr
Gainesville, GA 30501-2059
Registry dates
- Enumerated
- 2005-05-23
- Last updated
- 2008-05-29
Frequently asked questions
- What is William Callahan's NPI number?
- William Callahan's National Provider Identifier (NPI) is 1356344535, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Callahan's specialty?
- William Callahan is listed in the NPPES registry with a primary specialty of Specialist (Other Service Providers).
- Where is William Callahan located?
- William Callahan's practice location on file with NPPES is 663 Lanier Park Dr, Gainesville, GA 30501.
- What is William Callahan's phone number?
- The practice phone number listed in the NPPES registry for William Callahan is (770) 536-8109.
- Is William Callahan's NPI active?
- Yes — William Callahan's NPI (1356344535) is active in the NPPES registry as of the last update on 2008-05-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.