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Dr. Allen Chang, MD
NPI1225265051PAC ID3274795505
- Medicare services, 2024
- 84
- Medicare patients, 2024
- 88
- Part D claims, 2024
- 210
- Publications
- 9
- Hospital affiliations
- 1
- Practice address
- 55 North Ave, Mendon, MA 01756
- Practice phone
- Call (508) 334-1000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Umass Memorial Medical Center
Mendon, Massachusetts
Find Dr. Chang's professional email, personal email and mobile number
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Dr. Allen Chang is an internist in Mendon, Massachusetts
Dr. Chang practices at Umass Memorial Medical Center in Mendon, Massachusetts.
Dr. Chang's NPI, 1225265051, was assigned on June 19, 2009. Dr. Chang graduated from University of Massachusetts Medical School in 2009. Dr. Chang holds Massachusetts license 249481.
NPI and contact details
- NPI
- 1225265051NPI Registry (opens in a new tab)
- Medicare PAC ID
- 3274795505
- NPI enumeration date
- June 19, 2009
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (508) 334-1000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 43
- Medical school graduation
- 2009
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Allen Chang practices at Umass Memorial Medical Center in Mendon, Massachusetts
Dr. Chang's primary practice is Umass Memorial Medical Center, at 55 North Ave, Mendon, MA 01756 in Worcester County. The practice phone is (508) 334-1000.
- Umass Memorial Medical Center55 North Ave, Mendon, MA 01756 · Worcester CountyPhone(508) 334-1000
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Allen Chang is affiliated with 2 sites of care and 1 medical group
Dr. Chang's primary practice is Umass Memorial Medical Center in Mendon, Massachusetts. Dr. Chang is also affiliated with UMass Memorial Medical Center - University Campus. The medical group on file is UMass Memorial Medical Group.
Umass Memorial Medical CenterPrimary
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Allen Chang's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Chang practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Umass Memorial Medical Center | 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. Allen Chang is one of 5,528 internists in Massachusetts
Internal medicine is Dr. Chang's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Chang is licensed in Massachusetts.
Specialties and state licenses
- Internal medicine, MassachusettsPrimary
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. Allen Chang billed Medicare for 84 services in 2024
CMS data shows 84 Medicare services from Dr. Chang across 3 procedure codes in 2024, for 88 Medicare patients. Medicare paid $3,846 for them. Every service was in a facility, such as a hospital, rather than an office.
Medicare services, 202484
Medicare patients88
Paid by Medicare$3,846
Procedure codes3
Dr. Chang's Medicare services by type, 2022 to 2024
- 2022
- 2024
- Office and hospital visits
- 2022: 482024: 8475%
- Other services
- 2022: 172024: 0100%
- Surgery
- 2022: 502024: 0100%
Dr. Chang compared with the Massachusetts median for internists, 2024
- Dr. Chang
- Massachusetts median
- Medicare services
- 84vs 43181% below
- Medicare patients
- 88vs 19455% below
- Part D claims
- 68vs 40283% below
Medians across 5,369 internists in Massachusetts 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 Massachusetts.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Allen Chang treated 88 Medicare patients in 2024, average age 71
CMS counts 88 Medicare patients who saw Dr. Chang in 2024. The largest group is 65 to 74, with 31 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 41% are also on Medicaid. Their average risk score is 1.93, 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 47% women.
Medicare patients, 202488
Average age71
Average risk score1.93
Also on Medicaid41%
Dr. Chang's Medicare patients by age, 2024
Dr. Chang's Medicare patients by sex, 2024
- Women4753%
- Men4147%
Chronic conditions among Dr. Chang's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis44%
- Mood disorders44%
- Depression40%
- Diabetes39%
- Anxiety38%
- COPD34%
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
- Women47%
- Men52%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Allen Chang wrote 210 Medicare Part D claims in 2024
In 2024, Dr. Chang wrote 210 Medicare Part D claims for 105 patients. 84% of them were for generic drugs. CMS names the drug for 68 of them, across 4 drugs with 11 or more claims each, at $953 in total drug cost. In 2023, CMS named 292 claims across 14 drugs.
Part D claims, 2024210
Drugs named by CMS4
Total drug cost$953
Part D patients105
Dr. Chang's Part D claims by kind of drug, 2024
- Generic177 claims84%
- Brand-name and other33 claims16%
Dr. Chang's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Chang's Part D claims, 2024
- Antibiotics5%11 of 210 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 2922024: 6877%
Drugs named by CMS: 4 in 2024, 14 in 2023.
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
Dr. Allen Chang offers telehealth to Medicare patients
Dr. Chang accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Chang as offering telehealth.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Allen Chang has 9 publications on record
Dmand AI links 9 papers to Dr. Chang, published from 2021 to 2024. 2023 was the busiest year, with 4. The most frequent topics are Electroencephalography, Epilepsy, Temporal Lobe and Magnetic Resonance Imaging. Dr. Chang has published most often in Neurology. Dr. Chang's most frequent co-authors are Leonardo Fator Gouvea Bonilha, MD, PhD, Ezequiel Leonardo Gleichgerrcht, MD, PhD and Daniel Louis Drane, PhD.
Papers9
Years published2021 to 2024
Dr. Chang's papers by year, 2021 to 2024
Topics Dr. Chang writes about most
- Electroencephalography
- Epilepsy, Temporal Lobe
- Magnetic Resonance Imaging
- Seizures
- Brain
- Drug Resistant Epilepsy
- Stroke
- Temporal Lobe
Dr. Chang's most frequent co-authors
- Leonardo Fator Gouvea Bonilha, MD, PhD8 shared papers
- Ezequiel Leonardo Gleichgerrcht, MD, PhD5 shared papers
- Daniel Louis Drane, PhD3 shared papers
Recent publications by Dr. Chang
BrainDrug Resistant EpilepsyElectrocorticography
Epilepsy Behav
Diffusion Tensor ImagingElectroencephalographyEpilepsy
See who Dr. Chang researches with
Physician Network Discovery turns co-authorship, shared hospitals and shared groups into a map of who Dr. Chang works with, so you can find a warm path to the right internists.
Sources: PubMed (National Library of Medicine); and Dmand AI Research Linkage
Dr. Allen Chang graduated from University of Massachusetts Medical School
Dr. Chang graduated from University of Massachusetts Medical School in 2009.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Allen 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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand 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) |
| Publications, topics and co-authors | PubMed (National Library of Medicine) (opens in a new tab)Dmand AI Research Linkage |
| 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. Allen 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. Allen Chang's NPI number?
Dr. Allen Chang's NPI number is 1225265051. It was assigned on June 19, 2009, and it is active in the NPI Registry.
What kind of doctor is Dr. Allen Chang?
Dr. Allen Chang is an internist in Mendon, Massachusetts. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Allen Chang practice?
Dr. Chang practices at 55 North Ave, Mendon, MA 01756. Dr. Chang's primary practice is Umass Memorial Medical Center in Mendon, Massachusetts.
What is Dr. Allen Chang's office phone number?
The practice phone on file for Dr. Chang is (508) 334-1000.
What is Dr. Allen Chang's medical license number?
Dr. Chang holds Massachusetts license 249481.
Which hospitals is Dr. Allen Chang affiliated with?
Dr. Chang is affiliated with UMass Memorial Medical Center - University Campus.
What medical group is Dr. Allen Chang part of?
Dr. Chang is linked to UMass Memorial Medical Group.
Does Dr. Allen Chang accept Medicare?
Yes. CMS data shows Dr. Chang billed Medicare for 84 services in 2024, and Dr. Chang accepts Medicare assignment.
Does Dr. Allen Chang offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Dr. Chang as offering telehealth services.
How many Medicare patients does Dr. Allen Chang see?
CMS counts 88 Medicare patients who saw Dr. Chang in 2024, with an average age of 71.
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What services does Dr. Allen Chang bill to Medicare?
In 2024, Dr. Chang's most billed Medicare services were office visit, established patient (99214), office visit, established patient (99213) and care management and other visits (99495).
Where did Dr. Allen Chang go to medical school?
Dr. Chang graduated from University of Massachusetts Medical School in 2009.
What drugs does Dr. Allen Chang prescribe most?
In 2024 Medicare Part D data, Dr. Chang's most prescribed drugs by claims were Amlodipine Besylate, Atorvastatin Calcium and Levothyroxine Sodium.
How long has Dr. Allen Chang been practicing?
Dr. Chang graduated from medical school in 2009, 17 years ago.
Does Dr. Allen Chang do research?
Dmand AI links 9 publications to Dr. Chang, published from 2021 to 2024.
Who does Dr. Allen Chang publish with?
Dr. Chang's most frequent co-authors are Leonardo Fator Gouvea Bonilha, MD, PhD (8 shared papers), Ezequiel Leonardo Gleichgerrcht, MD, PhD (5 shared papers) and Daniel Louis Drane, PhD (3 shared papers).
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