Mark C O'Brien, D.O.
With over 39 years in internal medicine, Mark C O'Brien, D.O. is a long-established internist in Vista. A Michigan State University College of Osteopathic Medicine graduate since 1987, he brings 39+ years of experience. He regularly sees Medicare patients with hypertension, high cholesterol, and arthritis (per CMS claims data).
Older · 400dNPPES updated 2025-04-01 · verify on CMS
Contact & Location
Practice Location
161 Thunder Dr Ste 210, Vista, CA 92083-6052
How Does This Doctor Compare?
Medicare Patients
194
Unique beneficiaries
Standard volumePrescription Recipients
107
Patients prescribed
Prescriptions Written
230
Total claims
Total Medicare drug cost: $22k
Data Note: Sourced from CMS Medicare Provider Utilization & Payment Data. Percentile rankings compare this provider against all peers with reported data in the same state. Updated annually to reflect the latest federal reporting cycle.
What This Doctor Treats Most
Based on Medicare claims data — here's what patients commonly see this doctor for
Based on Medicare data, this doctor primarily manages Hypertension, High Cholesterol, and Arthritis.
High blood pressure — a leading risk factor for heart disease and stroke
Elevated cholesterol or triglycerides that increase heart disease risk
Joint inflammation causing pain, swelling, and stiffness
Gradual loss of kidney function over time, often linked to diabetes or hypertension
Reduced blood flow to the heart muscle, commonly known as coronary artery disease
The heart cannot pump blood efficiently enough to meet the body's needs
A condition where the body cannot properly regulate blood sugar levels
An irregular, often rapid heartbeat that increases the risk of stroke
Percentage of this provider's Medicare patients diagnosed with each condition. Source: CMS Utilization Data.
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Background & Specialty
Education, training, and specialty classification from CMS NPPES and Medicare records.
Graduated medical school · 1987
Michigan State University College of Osteopathic Medicine
Board certified · Mar 31, 2025
CMS-verified certification date
39 years in practice
Senior practitioner
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Taxonomy: 207R00000X
Education & Training
Michigan State University College of Osteopathic Medicine (Class of 1987)
Primary hospital affiliation: Acute Care Hospitals
CMS Certification Number: 190218
View hospital on Medicare Care CompareVirtual Internal Medicine Care With Mark C O'Brien
NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.
Schedule a virtual visit with Mark C O'Brien for blood pressure monitoring, cholesterol management, arthritis follow-ups — no travel to Vista required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes. Medicare enrolled per CMS records.
Frequently Asked Questions
Common questions about Mark C O'Brien
Dr. O'Brien is listed as active in the NPI registry with telehealth listed in Vista, CA. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (760) 216-6500.
Sourced from CMS NPPES · OIG LEIE · CMS Medicare Part D · CMS Physician Comparator. See Data Methodology.
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Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.
Contact Mark C O'Brien
Practice Location
161 Thunder Dr Ste 210, Vista, CA 92083-6052
Mailing Address
161 Thunder Dr Ste 210, Vista, CA 92083-6052
This is a provider directory. Contact the office directly to schedule appointments.
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