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MARK C O'BRIEN D.O.
NPI 1497744247
Internal Medicine in Vista, CA

Active since October 14, 2005PECOS EnrolledAccepts Medicare Assignment
161 THUNDER DR STE 210, VISTA, CA 92083(760) 216-6500(760) 295-4753 Get Directions Write a Review

NPPES record last updated: April 1, 2025. Verified against the NPPES registry weekly; last sync: August 09, 2026.

Record update history: Apr 1, 2025, Feb 26, 2025 (2 updates tracked since 2025).

About Mark C O'brien D.o. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MARK C O'BRIEN D.O. (NPI 1497744247) is an individual internal medicine provider in Vista, California, licensed in California (20A6017) and active in the NPI registry since October 2005. He is enrolled in Medicare PECOS and is a graduate of Michigan State University College Of Osteopathic Medicine (1987).

NPPES Registry Identity

NPI1497744247
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameMARK C O'BRIENCredential: D.O.
Location Address161 THUNDER DR STE 210Vista, CA 92083-6052
Mailing Address161 Thunder Dr Ste 210Vista, CA 92083-6052 · (760) 216-6500 · Fax (760) 295-4753
Phone(760) 216-6500
Fax(760) 295-4753
Sole ProprietorNo
Medical School CMSMichigan State University College Of Osteopathic MedicineGraduated 1987
Enumeration DateOctober 14, 2005
Last NPPES UpdateApril 1, 20252 updates tracked since enumeration
NPPES CertifiedApril 1, 2025
✔ NPI 1497744247 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in CA · 20A6017
Definition
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.
161 THUNDER DR STE 210, Vista, CA 92083
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Mark C O'brien D.o. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6103728118
PECOS Enrollment IDI20080307000443
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 4

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
276 services105 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
183 services76 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
107 services103 patients
Hospital discharge day management, more than 30 minutes 99239
Hospital discharge day management over 30 minutes involves a detailed process to ensure a smooth transition from hospital to home. It includes final examinations, discussion of your hospital stay, post-discharge instructions, and coordinating follow-up care.
91 services90 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92083 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$140.22 typical visit price
range $62.10 – $184.71
Typical copayment $35.05 (range $15.52 – $46.17)
Most-billed visit code 99204
Established Patient
$108.42 typical visit price
range $20.62 – $151.42
Typical copayment $27.10 (range $5.15 – $37.85)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

Reported Quality Measures

Care Plan
Percentage of patients aged 65 years and older who have an advance care plan or surrogate decision maker documented in the medical record that an advance care plan was discussed but the patient did not wish or was not able to name a surrogate decision maker…
83%70 patients4/55-star benchmark: 100%
Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Referred Medical Equipment & Supplies CMS DME claims 2

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Portable gaseous oxygen system, rental; includes portable container, regulator, flowmeter, humidifier, cannula or mask, and tubing E0431
DME-Oxygen and Supplies · category DC000N
1 supplier12 claims12 services$14.47 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
1 supplier13 claims13 services$58.74 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 2

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MARK C. O'BRIEN, D.O., INC.
Internal Medicine
161 THUNDER DR STE 210
VISTA, CA 92083
San Diego County (760) 889-1763
MS. MICHELLE MARIE VANAMAN RNFA, CNOR
Registered Nurse (Registered Nurse First Assistant)
161 THUNDER DR STE 210
VISTA, CA 92083
San Diego County (760) 724-0400

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mark O'brien's NPI number?

The NPI number for Mark O'brien is 1497744247. It was assigned to this individual provider in the NPPES registry on October 14, 2005.

Where is Mark O'brien located?

Mark O'brien practices at 161 Thunder Dr Ste 210, Vista, CA 92083. The listed phone number is (760) 216-6500.

What is Mark O'brien's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Mark O'brien enrolled in Medicare?

Yes. Mark O'brien is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

When was this NPI record last updated?

The NPPES record for Mark O'brien was last updated on April 1, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.