Quick answers
- Which hospitals does Matthew J. Obrien work at?
- Medicare's official clinician data lists Matthew J. Obrien at 1 hospital: Northwestern Memorial Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Matthew J. Obrien see patients?
- Medicare's clinician data lists 2 practice locations, including Chicago, IL. Call before your visit to confirm the address.
- What is Matthew J. Obrien's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Matthew J. Obrien accept Medicare assignment?
- Medicare's clinician data says Matthew J. Obrien may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is Matthew J. Obrien's NPI number?
- 1306900378. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Matthew J. Obrien works
Medicare's Facility Affiliation Data lists Matthew J. Obrien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Northwestern Memorial HospitalChicago, IL · Acute Care Hospital · CCN 140281
Practice locations
Addresses where Matthew J. Obrien is enrolled with Medicare (CMS data updated 2026-10-02).
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Chicago
Clinicians with the same Medicare primary specialty in Chicago, IL — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2004 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1306900378 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians