Mark C. O'Brien, D.O., Inc.
NPI 1346060860 · Internal Medicine Physician · Vista, CA
Enrolled with Medicare as Part B Supplier - Clinic/Group Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark C. O'Brien, D.O., Inc. is a Internal Medicine Physician organization in Vista, CA (NPI 1346060860).
Provider details
- NPI number
- 1346060860
- Entity type
- Organization
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Organization subpart
- No
- Authorized official
- Mark O'Brien, President(760) 889-1763
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
1 yr 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
- 2024-10-10
- Last updated
- 2024-10-10
- Certified
- 2024-10-10
Frequently asked questions
- What is Mark C. O'Brien, D.O., Inc.'s NPI number?
- Mark C. O'Brien, D.O., Inc.'s National Provider Identifier (NPI) is 1346060860, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is Mark C. O'Brien, D.O., Inc.?
- Mark C. O'Brien, D.O., Inc. is classified in the NPPES registry as Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mark C. O'Brien, D.O., Inc. located?
- Mark C. O'Brien, D.O., Inc.'s practice location on file with NPPES is 161 Thunder Dr Ste 210, Vista, CA 92083-6052.
- What is Mark C. O'Brien, D.O., Inc.'s phone number?
- The practice phone number listed in the NPPES registry for Mark C. O'Brien, D.O., Inc. is (760) 889-1763.
- Does Mark C. O'Brien, D.O., Inc. accept Medicare?
- Mark C. O'Brien, D.O., Inc. is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Who is the authorized official for Mark C. O'Brien, D.O., Inc.?
- The authorized official listed on Mark C. O'Brien, D.O., Inc.'s NPPES record is Mark O'Brien, President. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is Mark C. O'Brien, D.O., Inc.'s NPI active?
- Yes — Mark C. O'Brien, D.O., Inc.'s NPI (1346060860) is active in the NPPES registry as of the last update on 2024-10-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.