John O'Brien, MD
NPI 1639268584 · Family Medicine Physician · Chelsea, MI
John O'Brien, MD is a Family Medicine Physician provider in Chelsea, MI (NPI 1639268584).
Provider details
- NPI number
- 1639268584
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 4301043586 (MI)
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
19 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
Mailing address
Registry dates
- Enumerated
- 2006-10-11
- Last updated
- 2012-03-27
Frequently asked questions
- What is John O'Brien's NPI number?
- John O'Brien's National Provider Identifier (NPI) is 1639268584, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John O'Brien's specialty?
- John O'Brien is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is John O'Brien located?
- John O'Brien's practice location on file with NPPES is 14700 East Old US 12, Chelsea, MI 48118-1185.
- What is John O'Brien's phone number?
- The practice phone number listed in the NPPES registry for John O'Brien is (734) 475-1321.
- Is John O'Brien's NPI active?
- Yes — John O'Brien's NPI (1639268584) is active in the NPPES registry as of the last update on 2012-03-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.