Dr. Robert Chang, MD
- Medicare services, 2024
- 135
- Medicare patients, 2024
- 52
- Part D claims, 2024
- 63
- Hospital affiliations
- 1
- Industry payments
- $341
- 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. Chang's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Robert Chang is an internist in Ann Arbor, Michigan
Dr. Chang practices at University Hospital in Ann Arbor, Michigan.
Dr. Chang's NPI, 1720177686, was assigned on October 11, 2006. Dr. Chang graduated from University of Michigan Medical School in 2002. Dr. Chang holds Michigan license 4301079933.
- NPI
- 1720177686NPI Registry (opens in a new tab)
- Medicare PAC ID
- 2365475324
- NPI enumeration date
- October 11, 2006
- 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
- Male
- Estimated age
- 50
- Medical school graduation
- 2002
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Robert Chang practices at University Hospital in Ann Arbor, Michigan
Dr. Chang'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. Robert Chang is affiliated with 2 sites of care and 1 medical group
Dr. Chang's primary practice is University Hospital in Ann Arbor, Michigan. Dr. Chang is also affiliated with University Hospital. The medical group on file is University of Michigan Health. Dr. Chang'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. Robert Chang's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Chang 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 affiliated site | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Robert Chang is one of 4,804 internists in Michigan
Internal medicine is Dr. Chang's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Chang is licensed in Michigan.
Specialties and state licenses
- Internal medicine, MichiganPrimary
Internists near Dr. Chang
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. Robert Chang billed Medicare for 135 services in 2024
CMS data shows 135 Medicare services from Dr. Chang across 3 procedure codes in 2024, for 52 Medicare patients. Medicare paid $10,873 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Chang's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 982024: 13538%
Dr. Chang compared with the Michigan median for internists, 2024
- Dr. Chang
- Michigan median
- Medicare services
- 135vs 42368% below
- Medicare patients
- 52vs 15967% below
Medians across 4,524 internists in Michigan with Dmand AI profiles that report each measure.
Dr. Chang'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. Chang and other internists in Michigan.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Robert Chang treated 52 Medicare patients in 2024, average age 73
CMS counts 52 Medicare patients who saw Dr. Chang in 2024. The largest group is 75 to 84, with 22 patients. 75% of them have high blood pressure, and 75% have high cholesterol. Their average risk score is 2.46, 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. Chang's median patient age at 68, with 55% women.
Dr. Chang's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Chang's Medicare patients by sex, 2024
- Women2956%
- Men2344%
Chronic conditions among Dr. Chang's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Diabetes54%
- Arthritis52%
- Anxiety50%
- Chronic kidney disease48%
- Ischemic heart disease46%
- Heart failure38%
Share of Medicare patients with each condition. A patient can have several.
Dr. Chang's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 68
Patient panel by sex, all payers
- Women55%
- Men45%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Robert Chang wrote 63 Medicare Part D claims in 2024
In 2024, Dr. Chang wrote 63 Medicare Part D claims for 22 patients. 76% of them were for generic drugs.
Dr. Chang's Part D claims by kind of drug, 2024
- Generic48 claims76%
- Brand-name and other15 claims24%
Drug classes CMS tracks in Dr. Chang's Part D claims, 2024
- Antibiotics24%15 of 63 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Robert Chang takes part in Medicare
Dr. Chang 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. Robert Chang received $341 in industry payments from 2016 to 2024
CMS Open Payments shows 15 general payments to Dr. Chang from 7 drug and device companies from 2016 to 2024. Food and beverage make up the largest share, 100% of the total. Allergan Inc. paid the most, $137.
General payments to Dr. Chang by program year, 2016 to 2024
Companies that paid Dr. Chang the most, 2016 to 2024
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Robert Chang graduated from University of Michigan Medical School
Dr. Chang graduated from University of Michigan Medical School in 2002.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Robert Chang'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 (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) |
| Industry payments | Open Payments (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. Robert Chang
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Robert Chang's NPI number?
Dr. Robert Chang's NPI number is 1720177686. It was assigned on October 11, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Robert Chang?
Dr. Robert Chang is an internist in Ann Arbor, Michigan. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Robert Chang practice?
Dr. Chang practices at 1500 E Medical Center Dr, Ann Arbor, MI 48109. Dr. Chang's primary practice is University Hospital in Ann Arbor, Michigan.
What is Dr. Robert Chang's office phone number?
The practice phone on file for Dr. Chang is (734) 936-4000.
What is Dr. Robert Chang's medical license number?
Dr. Chang holds Michigan license 4301079933.
Which hospitals is Dr. Robert Chang affiliated with?
Dr. Chang is affiliated with University Hospital.
What medical group is Dr. Robert Chang part of?
Dr. Chang is linked to University of Michigan Health.
Does Dr. Robert Chang accept Medicare?
Yes. CMS data shows Dr. Chang billed Medicare for 135 services in 2024, and Dr. Chang accepts Medicare assignment.
How many Medicare patients does Dr. Robert Chang see?
CMS counts 52 Medicare patients who saw Dr. Chang in 2024, with an average age of 73.
What services does Dr. Robert Chang bill to Medicare?
In 2024, Dr. Chang's most billed Medicare services were hospital inpatient care (99233), hospital inpatient care (99232) and hospital inpatient care (99239).
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Where did Dr. Robert Chang go to medical school?
Dr. Chang graduated from University of Michigan Medical School in 2002.
Has Dr. Robert Chang received payments from drug or device companies?
CMS Open Payments shows $341 in general payments to Dr. Chang from 7 companies from 2016 to 2024. The largest total came from Allergan Inc.
How long has Dr. Robert Chang been practicing?
Dr. Chang graduated from medical school in 2002, 24 years ago.
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