John Halloran, DO
NPI 1851888697 · Internal Medicine Physician · Sacramento, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Halloran, DO is a Internal Medicine Physician provider in Sacramento, CA (NPI 1851888697).
Provider details
- NPI number
- 1851888697
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Male
- Sole proprietor
- No
- License
- 20A19224 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
8 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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 21 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 105 | 38 |
| Amlodipine Besylate | 77 | 25 |
| Lisinopril | 60 | 24 |
| Levothyroxine Sodium | 38 | 18 |
| Metformin Hcl | 33 | 16 |
| Losartan Potassium | 31 | 16 |
| Gabapentin |
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-04-17
- Last updated
- 2022-01-18
- Certified
- 2022-01-18
Frequently asked questions
- What is John Halloran's NPI number?
- John Halloran's National Provider Identifier (NPI) is 1851888697, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Halloran's specialty?
- John Halloran is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John Halloran located?
- John Halloran's practice location on file with NPPES is 3000 Q St Fl 3, Sacramento, CA 95816-7058.
- What is John Halloran's phone number?
- The practice phone number listed in the NPPES registry for John Halloran is (916) 733-3400.
- Does John Halloran accept Medicare?
- John Halloran is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Halloran's NPI active?
- Yes — John Halloran's NPI (1851888697) is active in the NPPES registry as of the last update on 2022-01-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.