Dr. Ruby Ann Marr, MD
- Medicare services, 2024
- 151
- Medicare patients, 2024
- 68
- Part D claims, 2024
- 55
- Hospital affiliations
- 1
- Medical groups
- 3
- Practice address
- 1500 E Medical Center Dr, Ann Arbor, MI 48109
- Practice phone
- Call (734) 936-4000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
University Hospital
School-Based Health Center · Ann Arbor, Michigan
Find Dr. Marr's professional email, personal email and mobile number
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Dr. Ruby Ann Marr is an internist in Ann Arbor, Michigan
Dr. Marr practices at University Hospital in Ann Arbor, Michigan.
Dr. Marr's NPI, 1952644700, was assigned on March 30, 2013. Dr. Marr graduated from Wayne State University School of Medicine in 2013. Dr. Marr holds Michigan license 4301103598.
- NPI
- 1952644700NPI Registry (opens in a new tab)
- Medicare PAC ID
- 6305139650
- NPI enumeration date
- March 30, 2013
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (734) 936-4000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Female
- Estimated age
- 39
- Medical school graduation
- 2013
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Ruby Ann Marr practices at University Hospital in Ann Arbor, Michigan
Dr. Marr's primary practice is University Hospital, at 1500 E Medical Center Dr, Ann Arbor, MI 48109. The practice phone is (734) 936-4000.
- University Hospital1500 E Medical Center Dr, Ann Arbor, MI 48109Phone(734) 936-4000
Source: Dmand AI Affiliation Data
Dr. Ruby Ann Marr is affiliated with 2 sites of care and 3 medical groups
Dr. Marr's primary practice is University Hospital in Ann Arbor, Michigan. Dr. Marr is also affiliated with University Hospital. The medical group on file is University of Michigan Health. Dmand AI also links Dr. Marr to 2 more medical groups, each named with a free account. Dr. Marr's employer is on file too: a school & student health.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Ruby Ann Marr's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Marr practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| University Hospital | Available with a free account |
| +1 more site and 2 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Ruby Ann Marr is one of 4,804 internists in Michigan
Internal medicine is Dr. Marr's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Marr is licensed in Michigan.
Specialties and state licenses
- Internal medicine, MichiganPrimary
Internists near Dr. Marr
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Ruby Ann Marr billed Medicare for 151 services in 2024
CMS data shows 151 Medicare services from Dr. Marr across 4 procedure codes in 2024, for 68 Medicare patients. Medicare paid $10,365 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Marr's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 3092024: 15151%
Dr. Marr compared with the Michigan median for internists, 2024
- Dr. Marr
- Michigan median
- Medicare services
- 151vs 42364% below
- Medicare patients
- 68vs 15957% below
- Part D claims
- 16vs 31495% below
Medians across 4,524 internists in Michigan with Dmand AI profiles that report each measure.
Dr. Marr's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Marr and other internists in Michigan.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Ruby Ann Marr treated 68 Medicare patients in 2024, average age 70
CMS counts 68 Medicare patients who saw Dr. Marr in 2024. The largest group is 65 to 74, with 22 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 37% are also on Medicaid. Their average risk score is 4.26, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Marr's median patient age at 63, with 46% women.
Dr. Marr's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Marr's Medicare patients by sex, 2024
- Women4465%
- Men2435%
Chronic conditions among Dr. Marr's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Chronic kidney disease66%
- Mood disorders60%
- Depression56%
- Diabetes54%
- Anxiety53%
- Heart failure53%
Share of Medicare patients with each condition. A patient can have several.
Dr. Marr's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 63
Patient panel by sex, all payers
- Women46%
- Men53%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Ruby Ann Marr wrote 55 Medicare Part D claims in 2024
In 2024, Dr. Marr wrote 55 Medicare Part D claims for 19 patients. 73% of them were for generic drugs. CMS names the drug for 16 of them, across 1 drug with 11 or more claims each, at $94 in total drug cost. In 2016, CMS named 27 claims across 2 drugs.
Dr. Marr's Part D claims by kind of drug, 2024
- Generic40 claims73%
- Brand-name15 claims27%
Dr. Marr's most prescribed drugs by claims, 2017
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Part D claims for drugs CMS names, 2016 to 2017
- 2016
- 2017
- Claims for drugs CMS names
- 2016: 272017: 1641%
Drugs named by CMS: 1 in 2017, 2 in 2016.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Ruby Ann Marr takes part in Medicare
Dr. Marr accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Ruby Ann Marr graduated from Wayne State University School of Medicine
Dr. Marr graduated from Wayne State University School of Medicine in 2013.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Ruby Ann Marr's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Ruby Ann Marr
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What is Dr. Ruby Ann Marr's NPI number?
Dr. Ruby Ann Marr's NPI number is 1952644700. It was assigned on March 30, 2013, and it is active in the NPI Registry.
What kind of doctor is Dr. Ruby Ann Marr?
Dr. Ruby Ann Marr is an internist in Ann Arbor, Michigan. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Ruby Ann Marr practice?
Dr. Marr practices at 1500 E Medical Center Dr, Ann Arbor, MI 48109. Dr. Marr's primary practice is University Hospital in Ann Arbor, Michigan. Dmand AI also links Dr. Marr to 2 medical groups.
What is Dr. Ruby Ann Marr's office phone number?
The practice phone on file for Dr. Marr is (734) 936-4000.
What is Dr. Ruby Ann Marr's medical license number?
Dr. Marr holds Michigan license 4301103598.
Which hospitals is Dr. Ruby Ann Marr affiliated with?
Dr. Marr is affiliated with University Hospital.
What medical group is Dr. Ruby Ann Marr part of?
Dr. Marr is linked to University of Michigan Health. Dmand AI links Dr. Marr to 2 more medical groups.
Does Dr. Ruby Ann Marr accept Medicare?
Yes. CMS data shows Dr. Marr billed Medicare for 151 services in 2024, and Dr. Marr accepts Medicare assignment.
How many Medicare patients does Dr. Ruby Ann Marr see?
CMS counts 68 Medicare patients who saw Dr. Marr in 2024, with an average age of 70.
What services does Dr. Ruby Ann Marr bill to Medicare?
In 2024, Dr. Marr's most billed Medicare services were hospital inpatient care (99232), hospital inpatient care (99233) and hospital inpatient care (99231).
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Where did Dr. Ruby Ann Marr go to medical school?
Dr. Marr graduated from Wayne State University School of Medicine in 2013.
What drugs does Dr. Ruby Ann Marr prescribe most?
In 2017 Medicare Part D data, Dr. Marr's most prescribed drugs by claims were Omeprazole.
How long has Dr. Ruby Ann Marr been practicing?
Dr. Marr graduated from medical school in 2013, 13 years ago.
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