Dr. Johnston Co, MD
- Part D claims, 2017
- 11
- Hospital affiliations
- 1
- State license
- 1
- Year NPI issued
- 2007
- Practice address
- 1800 N California St, Stockton, CA 95204
- Practice phone
- Call (209) 943-2000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Co'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. Johnston Co is a preventive medicine/occupational environmental medicine physician in Stockton, California
Dr. Co practices at Dignity Health - St. Joseph's Medical Center in Stockton, California, part of CommonSpirit Health.
Dr. Co's NPI, 1114044096, was assigned on March 23, 2007. Dr. Co graduated from Loma Linda University School Of Medicine in 1991. Dr. Co's California license number on file is G077293.
- NPI
- 1114044096NPI Registry (opens in a new tab)
- NPI enumeration date
- March 23, 2007
- NPI status
- Active
- Practice phone
- (209) 943-2000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Medical school graduation
- 1991
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Johnston Co practices at Dignity Health - St. Joseph's Medical Center in Stockton, California
Dr. Co's primary practice is Dignity Health - St. Joseph's Medical Center, at 1800 N California St, Stockton, CA 95204 in San Joaquin County. The practice phone is (209) 943-2000.
- Dignity Health - St. Joseph's Medical Center1800 N California St, Stockton, CA 95204 · San Joaquin CountyPhone(209) 943-2000
Source: Dmand AI Affiliation Data
Dr. Johnston Co is affiliated with 1 site of care
Dr. Co's primary practice is Dignity Health - St. Joseph's Medical Center in Stockton, California, part of CommonSpirit Health.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Johnston Co's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Co practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Dignity Health - St. Joseph's Medical Center | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Johnston Co is one of 83 preventive medicine/occupational environmental medicine physicians in California
Preventive medicine/occupational environmental medicine is Dr. Co's primary specialty in the NPI Registry, under taxonomy code 2083P0500X. Dr. Co has a license on file in California.
Specialties and state licenses
- Preventive medicine/occupational environmental medicine, CaliforniaPrimary
Preventive medicine/occupational environmental medicine physicians near Dr. Co
Counts of preventive medicine/occupational environmental medicine physicians 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. Johnston Co's patients have a median age of 44
Across all payers, Dmand AI patient panel data puts Dr. Co's median patient age at 44, with 39% women.
Dr. Co's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 44
Patient panel by sex, all payers
- Women39%
- Men60%
Source: Dmand AI Patient Panel Data
Dr. Johnston Co wrote 11 Medicare Part D claims in 2017
In 2017, Dr. Co wrote 11 Medicare Part D claims. They cover 1 drug, with $139 in total drug cost.
Dr. Co's most prescribed drugs by claims, 2017
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Source: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026
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Dr. Johnston Co graduated from Loma Linda University School Of Medicine
Dr. Co graduated from Loma Linda University School Of Medicine in 1991.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Johnston Co'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) |
| 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. Johnston Co
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. Johnston Co's NPI number?
Dr. Johnston Co's NPI number is 1114044096. It was assigned on March 23, 2007, and it is active in the NPI Registry.
What kind of doctor is Dr. Johnston Co?
Dr. Johnston Co is a preventive medicine/occupational environmental medicine physician in Stockton, California. The primary specialty in the NPI Registry is Preventive Medicine/Occupational Environmental Medicine Physician (taxonomy code 2083P0500X).
Where does Dr. Johnston Co practice?
Dr. Co practices at 1800 N California St, Stockton, CA 95204. Dr. Co's primary practice is Dignity Health - St. Joseph's Medical Center in Stockton, California, part of CommonSpirit Health.
What is Dr. Johnston Co's office phone number?
The practice phone on file for Dr. Co is (209) 943-2000.
What is Dr. Johnston Co's medical license number?
Dr. Co's California license number on file is G077293.
Which hospitals is Dr. Johnston Co affiliated with?
Dr. Co practices at Dignity Health - St. Joseph's Medical Center in Stockton, California.
Where did Dr. Johnston Co go to medical school?
Dr. Co graduated from Loma Linda University School Of Medicine in 1991.
What drugs does Dr. Johnston Co prescribe most?
In 2017 Medicare Part D data, Dr. Co's most prescribed drugs by claims were Diltiazem 24hr ER.
How long has Dr. Johnston Co been practicing?
Dr. Co graduated from medical school in 1991, 35 years ago.
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