Dr. Gregory H. Johnson, MD
- Medicare services, 2020
- 745
- Part D claims, 2024
- 17
- Hospital affiliations
- 1
- Industry payments
- $29
- State license
- 1
- Practice address
- 300 Hillmont Avenue, Ventura, CA 93003
- Practice phone
- Call (805) 652-6075
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Johnson's professional email, personal email and mobile number
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Dr. Gregory H. Johnson is a gastroenterologist in Ventura, California
Dr. Johnson practices at Ventura County Medical Center in Ventura, California, part of Ventura County Health Care Agency.
Dr. Johnson's NPI, 1952463762, was assigned on December 15, 2006. Dr. Johnson graduated from Feinberg School of Medicine in 1972. Dr. Johnson holds California license G25258.
- NPI
- 1952463762NPI Registry (opens in a new tab)
- NPI enumeration date
- December 15, 2006
- NPI status
- Active
- Practice phone
- (805) 652-6075
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Medical school graduation
- 1972
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Gregory H. Johnson practices at Ventura County Medical Center in Ventura, California
Dr. Johnson's primary practice is Ventura County Medical Center, at 300 Hillmont Avenue, Ventura, CA 93003 in Ventura County. The practice phone is (805) 652-6075.
- Ventura County Medical Center300 Hillmont Avenue, Ventura, CA 93003 · Ventura CountyPhone(805) 652-6075
Source: Dmand AI Affiliation Data
Dr. Gregory H. Johnson is affiliated with 3 sites of care
Dr. Johnson's primary practice is Ventura County Medical Center in Ventura, California, part of Ventura County Health Care Agency. Dmand AI also links Dr. Johnson to 1 physician office and 1 therapy and rehab clinic, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Gregory H. Johnson's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Johnson practices, 3 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Ventura County Medical Center | Available with a free account |
| +2 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across Ventura County Health Care Agency and 6.2K+ hospitals, with verified contacts in the same login.
Dr. Gregory H. Johnson is one of 1,977 gastroenterologists in California
Gastroenterology is Dr. Johnson's primary specialty in the NPI Registry, under taxonomy code 207RG0100X. Dr. Johnson is board certified in gastroenterology by the American Board of Internal Medicine. Dr. Johnson is licensed in California.
Specialties and state licenses
- Gastroenterology, CaliforniaPrimary
Gastroenterologists near Dr. Johnson
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. Gregory H. Johnson billed Medicare for 745 services in 2020
CMS data shows 745 Medicare services from Dr. Johnson across 11 procedure codes in 2020. Medicare paid $60,542 for them.
Dr. Johnson's Medicare services by type, 2019 to 2020
- 2019
- 2020
- Office and hospital visits
- 2019: 2,0032020: 52074%
- Surgery
- 2019: 6602020: 16974%
- Other services
- 2019: 1812020: 5669%
Where Dr. Johnson's Medicare services took place, 2020
- In an office32343%
- In a facility42257%
Dr. Johnson compared with the California median for gastroenterologists, 2020
- Dr. Johnson
- California median
- Medicare services
- 745vs 58627% above
- Part D claims
- 409vs 3808% above
Medians across 1,875 gastroenterologists in California with Dmand AI profiles that report each measure.
Dr. Johnson's most billed Medicare procedure codes, 2020
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. Johnson?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Johnson and other gastroenterologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Gregory H. Johnson's patients have a median age of 73
Across all payers, Dmand AI patient panel data puts Dr. Johnson's median patient age at 73, with 44% women.
Dr. Johnson's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 73
Patient panel by sex, all payers
- Women44%
- Men56%
Source: Dmand AI Patient Panel Data
Dr. Gregory H. Johnson wrote 17 Medicare Part D claims in 2024
In 2024, Dr. Johnson wrote 17 Medicare Part D claims. 100% of them were for generic drugs. They cover 10 drugs, with $71,959 in total drug cost. In 2019, CMS named 725 claims across 19 drugs.
Dr. Johnson's most prescribed drugs by claims, 2020
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, 2019 to 2020
- 2019
- 2020
- Claims for drugs CMS names
- 2019: 7252020: 40944%
Drugs named by CMS: 10 in 2020, 19 in 2019.
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. Gregory H. Johnson received $29 in industry payments in 2017
CMS Open Payments shows 2 general payments to Dr. Johnson from 2 drug and device companies in 2017. Food and beverage make up the largest share, 100% of the total. Intercept Pharmaceuticals, Inc. paid the most, $17.
Companies that paid Dr. Johnson 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. Gregory H. Johnson graduated from Feinberg School of Medicine
Dr. Johnson graduated from Feinberg School of Medicine in 1972.
- Medical school
- Board certified in gastroenterology
- Board certified in internal medicine
Source: Dmand AI Professional Profile Data
Sources for Dr. Gregory H. Johnson'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 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. Gregory H. Johnson
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. Gregory H. Johnson's NPI number?
Dr. Gregory H. Johnson's NPI number is 1952463762. It was assigned on December 15, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Gregory H. Johnson?
Dr. Gregory H. Johnson is a gastroenterologist in Ventura, California. The primary specialty in the NPI Registry is Gastroenterology Physician (taxonomy code 207RG0100X).
Where does Dr. Gregory H. Johnson practice?
Dr. Johnson practices at 300 Hillmont Avenue, Ventura, CA 93003. Dr. Johnson's primary practice is Ventura County Medical Center in Ventura, California, part of Ventura County Health Care Agency. Dmand AI also links Dr. Johnson to 1 physician office and 1 therapy and rehab clinic.
What is Dr. Gregory H. Johnson's office phone number?
The practice phone on file for Dr. Johnson is (805) 652-6075.
What is Dr. Gregory H. Johnson's medical license number?
Dr. Johnson holds California license G25258.
Which hospitals is Dr. Gregory H. Johnson affiliated with?
Dr. Johnson practices at Ventura County Medical Center in Ventura, California.
Does Dr. Gregory H. Johnson accept Medicare?
Yes. CMS data shows Dr. Johnson billed Medicare for 745 services in 2020.
Is Dr. Gregory H. Johnson board certified?
Yes. Dr. Johnson is board certified in gastroenterology by the American Board of Internal Medicine.
What services does Dr. Gregory H. Johnson bill to Medicare?
In 2020, Dr. Johnson's most billed Medicare services were office visit, established patient (99213), hospital inpatient care (99232) and surgery: digestive system (43239).
Where did Dr. Gregory H. Johnson go to medical school?
Dr. Johnson graduated from Feinberg School of Medicine in 1972.
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What drugs does Dr. Gregory H. Johnson prescribe most?
In 2020 Medicare Part D data, Dr. Johnson's most prescribed drugs by claims were Omeprazole, Budesonide EC and Mesalamine.
Has Dr. Gregory H. Johnson received payments from drug or device companies?
CMS Open Payments shows $29 in general payments to Dr. Johnson from 2 companies from 2017 to 2017. The largest total came from Intercept Pharmaceuticals, Inc.
How long has Dr. Gregory H. Johnson been practicing?
Dr. Johnson graduated from medical school in 1972, 54 years ago.
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