Mark Obrien, MD
NPI 1235188525 · Internal Medicine Physician · Grand Rapids, MI
Mark Obrien, MD is a Internal Medicine Physician provider in Grand Rapids, MI (NPI 1235188525).
Provider details
- NPI number
- 1235188525
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- MO048187 (MI)
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
20 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
- 2006-05-06
- Last updated
- 2026-06-07
Frequently asked questions
- What is Mark Obrien's NPI number?
- Mark Obrien's National Provider Identifier (NPI) is 1235188525, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Obrien's specialty?
- Mark Obrien is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Obrien located?
- Mark Obrien's practice location on file with NPPES is 4070 Lake Dr Se, Grand Rapids, MI 49546-8294.
- What is Mark Obrien's phone number?
- The practice phone number listed in the NPPES registry for Mark Obrien is (616) 774-8200.
- Is Mark Obrien's NPI active?
- Yes — Mark Obrien's NPI (1235188525) is active in the NPPES registry as of the last update on 2026-06-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.