Mark Samuel Johnson, ASCP, MT, PA-C
- Medicare patients, 2024
- 235
- Part D claims, 2024
- 543
- Hospital affiliations
- 2
- Industry payments
- $32
- Medical groups
- 7
- Practice address
- 10 Hospital Dr, Saint Peters, MO 63376
- Practice phone
- Call (636) 916-9000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Mark Johnson'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.
Mark Samuel Johnson is a physician assistant in Saint Peters, Missouri
Mark Johnson practices at Barnes-Jewish St. Peters Hospital in Saint Peters, Missouri, part of BJC Health.
Mark Johnson's NPI, 1568453132, was assigned on November 2, 2005. Mark Johnson holds Missouri license 2010013488.
- NPI
- 1568453132NPI Registry (opens in a new tab)
- NPI enumeration date
- November 2, 2005
- NPI status
- Active
- Practice phone
- (636) 916-9000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 48
- Medical school graduation
- 2004
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Mark Samuel Johnson practices at Barnes-Jewish St. Peters Hospital in Saint Peters, Missouri
Mark Johnson's primary practice is Barnes-Jewish St. Peters Hospital, at 10 Hospital Dr, Saint Peters, MO 63376 in St. Charles County. The practice phone is (636) 916-9000.
- Barnes-Jewish St. Peters Hospital10 Hospital Dr, Saint Peters, MO 63376 · St. Charles CountyPhone(636) 916-9000
Source: Dmand AI Affiliation Data
Mark Samuel Johnson is affiliated with 2 sites of care and 7 medical groups
Mark Johnson's primary practice is Barnes-Jewish St. Peters Hospital in Saint Peters, Missouri, part of BJC Health. Mark Johnson is also affiliated with Select Specialty Hospital - St. Louis. The medical group on file is Vituity. Dmand AI also links Mark Johnson to 6 more medical groups, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Mark Samuel Johnson's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Mark Johnson practices, 2 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Barnes-Jewish St. Peters Hospital | Available with a free account |
| +1 more site and 6 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Mark Samuel Johnson is one of 1,484 physician assistants in Missouri
Physician assistant is Mark Johnson's primary specialty in the NPI Registry, under taxonomy code 363A00000X. Mark Johnson is licensed in Missouri.
Specialties and state licenses
- Physician assistant, MissouriPrimary
Physician assistants near Mark Johnson
Counts of physician assistants 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
Mark Samuel Johnson treated 235 Medicare patients in 2024, average age 75
CMS counts 235 Medicare patients who saw Mark Johnson in 2024. The largest group is 75 to 84, with 81 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 29% are also on Medicaid. Their average risk score is 2.36, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Mark Johnson's median patient age at 71, with 46% women.
Mark Johnson's Medicare patients by age, 2024
Mark Johnson's Medicare patients by sex, 2024
- Women13357%
- Men10243%
Chronic conditions among Mark Johnson's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis59%
- Chronic kidney disease49%
- Anxiety46%
- Diabetes46%
- Mood disorders46%
- Depression41%
Share of Medicare patients with each condition. A patient can have several.
Mark 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 71
Patient panel by sex, all payers
- Women46%
- Men54%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Mark Samuel Johnson wrote 543 Medicare Part D claims in 2024
In 2024, Mark Johnson wrote 543 Medicare Part D claims for 212 patients. 88% of them were for generic drugs.
Mark Johnson's Part D claims by kind of drug, 2024
- Generic477 claims88%
- Brand-name and other66 claims12%
Drug classes CMS tracks in Mark Johnson's Part D claims, 2024
- Opioids13%73 of 543 claims
- Antibiotics15%79 of 543 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Source: Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Mark Samuel Johnson received $32 in industry payments in 2025
CMS Open Payments shows 2 general payments to Mark Johnson from 2 drug and device companies in 2025. Food and beverage make up the largest share, 100% of the total. SK Life Science, Inc. paid the most, $18.
Companies that paid Mark Johnson the most, 2025 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Sources for Mark Samuel 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 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 (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| 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 Mark Samuel 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 Mark Samuel Johnson's NPI number?
Mark Samuel Johnson's NPI number is 1568453132. It was assigned on November 2, 2005, and it is active in the NPI Registry.
What does Mark Samuel Johnson specialize in?
Mark Samuel Johnson is a physician assistant in Saint Peters, Missouri. The primary specialty in the NPI Registry is Physician Assistant (taxonomy code 363A00000X).
Where does Mark Samuel Johnson practice?
Mark Johnson practices at 10 Hospital Dr, Saint Peters, MO 63376. Mark Johnson's primary practice is Barnes-Jewish St. Peters Hospital in Saint Peters, Missouri, part of BJC Health. Dmand AI also links Mark Johnson to 6 medical groups.
What is Mark Samuel Johnson's office phone number?
The practice phone on file for Mark Johnson is (636) 916-9000.
What is Mark Samuel Johnson's medical license number?
Mark Johnson holds Missouri license 2010013488.
Which hospitals is Mark Samuel Johnson affiliated with?
Mark Johnson practices at Barnes-Jewish St. Peters Hospital in Saint Peters, Missouri. Mark Johnson is also affiliated with Select Specialty Hospital - St. Louis.
What medical group is Mark Samuel Johnson part of?
Mark Johnson is linked to Vituity. Dmand AI links Mark Johnson to 6 more medical groups.
How many Medicare patients does Mark Samuel Johnson see?
CMS counts 235 Medicare patients who saw Mark Johnson in 2024, with an average age of 75.
Has Mark Samuel Johnson received payments from drug or device companies?
CMS Open Payments shows $32 in general payments to Mark Johnson from 2 companies from 2025 to 2025. The largest total came from SK Life Science, Inc.
How long has Mark Samuel Johnson been practicing?
Mark Johnson graduated from medical school in 2004, 22 years ago.
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