Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Internal Medicine

Ruby Marr, MD

Works at hospitals in Ann Arbor, MI · Michigan

Summary

Ruby Marr, MD (Internal Medicine) is listed by Medicare at 1 hospital in Ann Arbor, MI. NPI 1952644700. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Ruby Marr, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Internal MedicinePrimary specialty
YesAccepts Medicare assignment
13Years since medical school (graduated 2013)
Wayne State University School Of MedicineMedical school
FemaleGender (as listed)
Regents of the University of MichiganGroup practice

Quick answers

Which hospitals does Ruby Marr work at?
Medicare's official clinician data lists Ruby Marr at 1 hospital: University of Michigan Health System. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Ruby Marr see patients?
Medicare's clinician data lists 12 practice locations, including Ann Arbor, MI. Call before your visit to confirm the address.
What is Ruby Marr's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Ruby Marr accept Medicare assignment?
Yes. Medicare's clinician data says Ruby Marr accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
What is the phone number for Ruby Marr?
(734) 936-5738, as listed in official Medicare / NPI Registry data.
What is Ruby Marr's NPI number?
1952644700. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Ruby Marr works

Medicare's Facility Affiliation Data lists Ruby Marr at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Ruby Marr is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 12; the Medicare profile lists all.

Group practices

Medicare enrollment lists Ruby Marr as a member of this group (CMS data updated 2026-10-02).

  • Regents of the University of Michigan3,346 clinicians in the group

Specialties

Find other Internal Medicine doctors in Michigan →

Other internal medicine doctors in Ann Arbor

Clinicians with the same Medicare primary specialty in Ann Arbor, MI — not a recommendation.

All internal medicine doctors in Ann Arbor →

Clinician information

CredentialMD
Medical schoolWayne State University School Of Medicine
Graduation year2013
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1952644700
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians