DR. MARK T. O'BRIEN (D.O.) – Family Medicine Physician, NPI 1255322509

DR. MARK T. O'BRIEN (D.O.) is a healthcare provider. based in East china, Michigan. specializing in Family Medicine Physician. They hold the professional credentials D.O.. They hold a License No. 5101009744 (MI). The NPI Number for DR. MARK T. O'BRIEN (D.O.) is 1255322509

Main info

Male
Sole Proprietor
40 Years Of Experience
Accepts Medicare Assignment
Name
DR. MARK T. O'BRIEN (D.O.)
NPI
1255322509
Phone
(810) 329-4660
Address
4150 River Rd
Enumeration Date
3 November 2005
Last Update Date
25 February 2022

Doctor Profile

Medical School Name
OTHER
Secondary Phone
-
Graduation Year
1986 (40 years ago)
PAC ID
0042319964
Professional Enrollment ID
I20070619000109
Data current as of
19 May 2026

Profile Insights

NPPES metrics only — not quality of care.

Methodology
Experience64
Completeness75
Years active:20State licenses:1Digital endpointsOther names

Provider Addresses for DR. MARK T. O'BRIEN (D.O.)

  • 4150 River Rd

    Suite F2

    East China, MI 480542915

    Phone: (810) 329-4660

    Fax: (810) 329-4699

    Type: Location

  • 4150, River Road, Hawthorne, SaintClair, East China Township, Saint Clair County, Michigan, 48054, United States

    SUITE F2

    EAST CHINA, MI 480542915

    Phone: (810) 329-4660

    Fax: (810) 329-4699

    Type: Mailing

  • 1280 S 9TH ST

    SAINT CLAIR, MI 480795368

    Phone: (810) 326-0837

    Fax: (810) 326-1534

    Type: Mailing

NPPES updates history

No NPPES updates recorded for this provider.

Prescription Activity

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Open Payments (CMS)

No Open Payments data available for this provider.

This can happen when there are no reportable CMS Open Payments records.

Medicare Enrollment & Revalidation

Source: CMS public data · Not endorsed by CMS ·

Educational use only—not medical, billing, or legal advice.

PECOS enrollment status

Participating (accepts Medicare assignment)

Enrollment effective: 2007-06-19

PECOS data refreshed: 2026-05-27

Medicare revalidation (CMS due date list)

Due date not assigned yet

CMS is tracking this Medicare enrollment for revalidation, but has not published a due date.

Enrollment records

1

Earliest due date

Not assigned (TBD)

CMS data updated

2026-06-01

Revalidation progress

  1. Medicare enrolled
  2. On CMS revalidation list
  3. Due date assigned
  4. Revalidate in PECOS

CMS enrollment records

Enrollment IDTypeSpecialtyStateDue date
I20070619000109IFamily PracticeMITBD

What to do next

  • No action required while the due date shows TBD.
  • Check the CMS Revalidation Lookup Tool periodically — CMS updates the list about every 60 days.
  • Do not submit a revalidation application in PECOS until CMS publishes a concrete due date.

Verify on CMS Revalidation Lookup Tool

Prepare CMS-855 application → · Look up this NPI in PECOS → · Verify on CMS PECOS

Medicare Utilization (FFS)

Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·

Educational use only—not medical, billing, or legal advice.

Top Medicare procedures (2023) · refreshed 2026-05-27

HCPCSDescriptionServicesBeneficiariesMedicare allowed
99213Established patient office or other outpatient visit, 20-29 minutes12664$0
99214Established patient office or other outpatient visit, 30-39 minutes12062$0
36415Insertion of needle into vein for collection of blood sample9162$0
G0439Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit5959$0
99215Established patient office or other outpatient visit, 40-54 minutes2317$0
View full utilization report →

Insurance plans in this area (ZIP 48054)

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Reviews

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Frequently asked questions

What is the 10-digit NPI for DR. MARK T. O'BRIEN (D.O.)?
DR. MARK T. O'BRIEN (D.O.) — NPI 1255322509 — is the standard way to identify this listing.
Can I rely on DR. MARK T. O'BRIEN (D.O.) being an active provider?
As of the registry snapshot, DR. MARK T. O'BRIEN (D.O.) is marked active.
What healthcare role does DR. MARK T. O'BRIEN (D.O.) hold?
Scheduling teams often label DR. MARK T. O'BRIEN (D.O.) under Family Medicine Physician. Clinical services aligned with this taxonomy classification.
Where should I expect DR. MARK T. O'BRIEN (D.O.) on a map?
Expect East China, Michigan as a primary anchor for DR. MARK T. O'BRIEN (D.O.) unless the record lists multiple sites.
Why does DR. MARK T. O'BRIEN (D.O.) have multiple addresses?
5 practice locations appear in the available data. Multiple addresses are common for hospital privileges, telehealth, or multi-site groups.

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