NPI age
21 years
Enumerated 2005-05-23
● Active
Type 1 · Individual
William Thomas Callahan, MD
Callahan is 1 of 21 specialist providers in Gainesville and 1 of 1881 in Georgia.
Primary specialty
Specialist
Licensed in
GA
1 state
Status
Active
No deactivations on record
Last NPPES update
2008-05-29
Source: monthly bulk 2026-05
Sole proprietor
No
May be part of a larger org
How this provider compares
Across 1881 active specialist providers in Georgia.
NPI age
21 years
↑ 2 yr above median (19 yr)
State licenses
1 state
1% of peers hold multiple states
Subspecialties
0
7% of peers hold subspecialties
NPI lifetime · 2005 → 2026
2005-05Enumerated in NPPES
2005
2026
Where they practice
Practice location
663 Lanier Park Dr
Gainesville, GA 30501
Mailing address
663 Lanier Park Dr
Gainesville, GA 305012059
Specialties
-
Specialist PrimaryAn individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.
Identifiers
| Type | Value | Notes |
|---|---|---|
| 05 (GA) | 00162126A |
Practice context
Part of a multi-provider practice. 27 other active providers share this practice address in NPPES.
Recently enumerated nearby: 1 new specialist provider has been added in Gainesville in the last 180 days.
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- Confirm the NPI on NPPES.The CMS registry is the system of record. Open NPPES →
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