Dr. Greg N. Matsubara, MD
- Part D claims, 2024
- 3,679
- Industry payments
- $97
- Medical group
- 1
- State license
- 1
- Year NPI issued
- 2006
- Practice address
- 7300 North Fresno St, Fresno, CA 93720
- Practice phone
- Call (559) 448-4500
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Matsubara'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. Greg N. Matsubara is an internist in Fresno, California
Dr. Matsubara practices at Kaiser Permanente Fresno Medical Center in Fresno, California, part of Kaiser Permanente.
Dr. Matsubara's NPI, 1659459568, was assigned on November 1, 2006. Dr. Matsubara graduated from UC Davis School of Medicine in 1990. Dr. Matsubara holds California license G72470.
- NPI
- 1659459568NPI Registry (opens in a new tab)
- NPI enumeration date
- November 1, 2006
- NPI status
- Active
- Practice phone
- (559) 448-4500
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 62
- Medical school graduation
- 1990
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Greg N. Matsubara practices at Kaiser Permanente Fresno Medical Center in Fresno, California
Dr. Matsubara's primary practice is Kaiser Permanente Fresno Medical Center, at 7300 North Fresno St, Fresno, CA 93720 in Fresno County. The practice phone is (559) 448-4500.
- Kaiser Permanente Fresno Medical Center7300 North Fresno St, Fresno, CA 93720 · Fresno CountyPhone(559) 448-4500
Source: Dmand AI Affiliation Data
Dr. Greg N. Matsubara is affiliated with 1 medical group
Dr. Matsubara's primary practice is Kaiser Permanente Fresno Medical Center in Fresno, California, part of Kaiser Permanente. The medical group on file is The Permanente Medical Group, Inc.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Greg N. Matsubara's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Matsubara practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Kaiser Permanente Fresno Medical Center | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Greg N. Matsubara is one of 16,751 internists in California
Internal medicine is Dr. Matsubara's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Matsubara is board certified in internal medicine by the American Board of Internal Medicine. Dr. Matsubara is licensed in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Clinical focus
Dmand AI lists chest wall injury, itchy rashes, pneumonia and upper respiratory infection (URI) among the conditions Dr. Matsubara treats.
Internists near Dr. Matsubara
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. Greg N. Matsubara's patients have a median age of 66
Across all payers, Dmand AI patient panel data puts Dr. Matsubara's median patient age at 66, with 46% women.
Dr. Matsubara's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 66
Patient panel by sex, all payers
- Women46%
- Men54%
Source: Dmand AI Patient Panel Data
Dr. Greg N. Matsubara wrote 3,679 Medicare Part D claims in 2024
In 2024, Dr. Matsubara wrote 3,679 Medicare Part D claims for 524 patients. 92% of them were for generic drugs. CMS names the drug for 3,134 of them, across 59 drugs with 11 or more claims each, at $79,322 in total drug cost. In 2023, CMS named 7,294 claims across 115 drugs.
Dr. Matsubara's Part D claims by kind of drug, 2024
- Generic3,382 claims92%
- Brand-name237 claims6%
- Other60 claims2%
Dr. Matsubara'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. Matsubara's Part D claims, 2024
- Opioids1%29 of 3,679 claims
- Antibiotics1%30 of 3,679 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: 7,2942024: 3,13457%
Drugs named by CMS: 59 in 2024, 115 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
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Dr. Greg N. Matsubara received $97 in industry payments in 2017
CMS Open Payments shows 1 general payment to Dr. Matsubara from 1 drug or device company in 2017. Food and beverage make up the largest share, 100% of the total. Boston Scientific Corporation paid the most, $97.
Companies that paid Dr. Matsubara the most, 2017 to 2017
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Greg N. Matsubara graduated from UC Davis School of Medicine
Dr. Matsubara graduated from UC Davis School of Medicine in 1990.
- Medical school
- Board certified in internal medicine
Source: Dmand AI Professional Profile Data
Sources for Dr. Greg N. Matsubara'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 patients and the all-payer patient panel | Dmand AI Patient Panel Data |
| 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) |
| 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. Greg N. Matsubara
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. Greg N. Matsubara's NPI number?
Dr. Greg N. Matsubara's NPI number is 1659459568. It was assigned on November 1, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Greg N. Matsubara?
Dr. Greg N. Matsubara is an internist in Fresno, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Greg N. Matsubara practice?
Dr. Matsubara practices at 7300 North Fresno St, Fresno, CA 93720. Dr. Matsubara's primary practice is Kaiser Permanente Fresno Medical Center in Fresno, California, part of Kaiser Permanente.
What is Dr. Greg N. Matsubara's office phone number?
The practice phone on file for Dr. Matsubara is (559) 448-4500.
What is Dr. Greg N. Matsubara's medical license number?
Dr. Matsubara holds California license G72470.
Which hospitals is Dr. Greg N. Matsubara affiliated with?
Dr. Matsubara practices at Kaiser Permanente Fresno Medical Center in Fresno, California.
What medical group is Dr. Greg N. Matsubara part of?
Dr. Matsubara is linked to The Permanente Medical Group, Inc.
Is Dr. Greg N. Matsubara board certified?
Yes. Dr. Matsubara is board certified in internal medicine by the American Board of Internal Medicine.
Where did Dr. Greg N. Matsubara go to medical school?
Dr. Matsubara graduated from UC Davis School of Medicine in 1990.
What drugs does Dr. Greg N. Matsubara prescribe most?
In 2024 Medicare Part D data, Dr. Matsubara's most prescribed drugs by claims were Atorvastatin Calcium, Amlodipine Besylate and Losartan Potassium.
Has Dr. Greg N. Matsubara received payments from drug or device companies?
CMS Open Payments shows $97 in general payments to Dr. Matsubara from 1 company from 2017 to 2017. The largest total came from Boston Scientific Corporation.
How long has Dr. Greg N. Matsubara been practicing?
Dr. Matsubara graduated from medical school in 1990, 36 years ago.
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