Dr. John W. Roark Jr., MD
- Medicare services, 2022
- 12
- Part D claims, 2024
- 12
- MIPS score, 2024
- 95
- Medical group
- 1
- State license
- 1
- Practice address
- 2500 Alhambra Ave, Martinez, CA 94553
- Practice phone
- Call (925) 370-5955
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Martinez Health Center
Martinez, California
Find Dr. Roark'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. John W. Roark Jr. is a gastroenterologist in Martinez, California
Dr. Roark practices at Martinez Health Center in Martinez, California.
Dr. Roark's NPI, 1609834266, was assigned on May 3, 2006. Dr. Roark graduated from University of California, Geffen School of Medicine in 1977. Dr. Roark holds California license G038581.
- NPI
- 1609834266NPI Registry (opens in a new tab)
- NPI enumeration date
- May 3, 2006
- NPI status
- Active
- Practice phone
- (925) 370-5955
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 75
- Medical school graduation
- 1977
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Practice Data
Dr. John W. Roark Jr. practices at Martinez Health Center in Martinez, California
Dr. Roark's primary practice is Martinez Health Center, at 2500 Alhambra Ave, Martinez, CA 94553 in Contra Costa County. The practice phone is (925) 370-5955.
- Martinez Health Center2500 Alhambra Ave, Martinez, CA 94553 · Contra Costa CountyPhone(925) 370-5955
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. John W. Roark Jr. is affiliated with 1 site of care and 1 medical group
Dr. Roark's primary practice is Martinez Health Center in Martinez, California. The medical group on file is Alameda Health System.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. John W. Roark Jr.'s practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Roark practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Martinez Health Center | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. John W. Roark Jr. is one of 1,977 gastroenterologists in California
Gastroenterology is Dr. Roark's primary specialty in the NPI Registry, under taxonomy code 207RG0100X. Dr. Roark is licensed in California.
Specialties and state licenses
- Gastroenterology, CaliforniaPrimary
Gastroenterologists near Dr. Roark
Counts of gastroenterologists 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. John W. Roark Jr. billed Medicare for 12 services in 2022
CMS data shows 12 Medicare services from Dr. Roark across 1 procedure code in 2022. Medicare paid $872 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Roark's Medicare services by type, 2018 to 2022
- 2018
- 2022
- Surgery
- 2018: 272022: 1256%
Dr. Roark compared with the California median for gastroenterologists, 2022
- Dr. Roark
- California median
- Medicare services
- 12vs 58698% below
- Part D claims
- 17vs 38096% below
Medians across 1,875 gastroenterologists in California with Dmand AI profiles that report each measure.
Dr. Roark's most billed Medicare procedure codes, 2022
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
Need commercial claims for Dr. Roark?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Roark and other gastroenterologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. John W. Roark Jr.'s patients have a median age of 56
Across all payers, Dmand AI patient panel data puts Dr. Roark's median patient age at 56, with 0% women.
Dr. Roark's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 56
Patient panel by sex, all payers
- Women0%
- Men100%
Source: Dmand AI Patient Panel Data
Dr. John W. Roark Jr. wrote 12 Medicare Part D claims in 2024
In 2024, Dr. Roark wrote 12 Medicare Part D claims. 100% of them were for generic drugs. They cover 1 drug, with $318 in total drug cost. In 2018, CMS named 44 claims across 2 drugs.
Dr. Roark's most prescribed drugs by claims, 2019
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, 2018 to 2019
- 2018
- 2019
- Claims for drugs CMS names
- 2018: 442019: 1761%
Drugs named by CMS: 1 in 2019, 2 in 2018.
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. John W. Roark Jr. scored 95 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 95 out of 100 for Dr. Roark for performance year 2024, reported as part of a group.
Dr. Roark's MIPS scores, performance year 2024
- 95of 100Final score
- 86.9of 100Quality
- 100of 100Promoting Interoperability
- 40of 100Improvement Activities
- 73of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Source: Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Dr. John W. Roark Jr. graduated from University of California, Geffen School of Medicine
Dr. Roark graduated from University of California, Geffen School of Medicine in 1977.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. John W. Roark Jr.'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 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 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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Clinician Public Reporting: Overall MIPS Performance (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. John W. Roark Jr.
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. John W. Roark Jr.'s NPI number?
Dr. John W. Roark Jr.'s NPI number is 1609834266. It was assigned on May 3, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. John W. Roark Jr.?
Dr. John W. Roark Jr. is a gastroenterologist in Martinez, California. The primary specialty in the NPI Registry is Gastroenterology Physician (taxonomy code 207RG0100X).
Where does Dr. John W. Roark Jr. practice?
Dr. Roark practices at 2500 Alhambra Ave, Martinez, CA 94553. Dr. Roark's primary practice is Martinez Health Center in Martinez, California.
What is Dr. John W. Roark Jr.'s office phone number?
The practice phone on file for Dr. Roark is (925) 370-5955.
What is Dr. John W. Roark Jr.'s medical license number?
Dr. Roark holds California license G038581.
What medical group is Dr. John W. Roark Jr. part of?
Dr. Roark is linked to Alameda Health System.
Does Dr. John W. Roark Jr. accept Medicare?
Yes. CMS data shows Dr. Roark billed Medicare for 12 services in 2022.
What is Dr. John W. Roark Jr.'s MIPS score?
Dr. Roark's MIPS final score for performance year 2024 is 95 out of 100, reported as part of a group.
What services does Dr. John W. Roark Jr. bill to Medicare?
In 2022, Dr. Roark's most billed Medicare services were surgery: digestive system (43239).
Where did Dr. John W. Roark Jr. go to medical school?
Dr. Roark graduated from University of California, Geffen School of Medicine in 1977.
What drugs does Dr. John W. Roark Jr. prescribe most?
In 2019 Medicare Part D data, Dr. Roark's most prescribed drugs by claims were Omeprazole.
How long has Dr. John W. Roark Jr. been practicing?
Dr. Roark graduated from medical school in 1977, 49 years ago.
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