Christopher Callahan, MD
NPI 1104867043 · Geriatric Medicine (Internal Medicine) Physician · Indianapolis, IN
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Christopher Callahan, MD is a Geriatric Medicine (Internal Medicine) Physician provider in Indianapolis, IN (NPI 1104867043).
Provider details
- NPI number
- 1104867043
- Entity type
- Individual
- Primary specialty
- Geriatric Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 01036319A (IN)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
2 documented practice locations
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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 2 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Donepezil Hcl | 23 |
| Memantine Hcl | 19 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Additional practice locations (1)
- 720 Eskenazi AveIndianapolis, IN 46202-5187Phone: (317) 880-7666
Registry dates
- Enumerated
- 2006-06-10
- Last updated
- 2025-09-15
- Certified
- 2025-09-15
Frequently asked questions
- What is Christopher Callahan's NPI number?
- Christopher Callahan's National Provider Identifier (NPI) is 1104867043, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Christopher Callahan's specialty?
- Christopher Callahan is listed in the NPPES registry with a primary specialty of Geriatric Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Christopher Callahan located?
- Christopher Callahan's practice location on file with NPPES is 1633 N Capitol Ave, Indianapolis, IN 46202-1476.
- What is Christopher Callahan's phone number?
- The practice phone number listed in the NPPES registry for Christopher Callahan is (317) 962-2929.
- Does Christopher Callahan accept Medicare?
- Christopher Callahan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Christopher Callahan's NPI active?
- Yes — Christopher Callahan's NPI (1104867043) is active in the NPPES registry as of the last update on 2025-09-15.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.