Dr. Thomas Mark Johnson, MD
- Medicare services, 2024
- 896
- Medicare patients, 2024
- 371
- Part D claims, 2024
- 2,993
- Hospital affiliations
- 2
- Industry payments
- $1,231
- Practice address
- 1000 Langworthy St, Dubuque, IA 52001
- Practice phone
- Call (563) 584-4100
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Medical Associates Clinic P C
Dubuque, Iowa
Find Dr. 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.
Dr. Thomas Mark Johnson is a cardiologist in Dubuque, Iowa
Dr. Johnson practices at Medical Associates Clinic P C in Dubuque, Iowa.
Dr. Johnson's NPI, 1801848486, was assigned on May 16, 2006. Dr. Johnson graduated from University of Iowa, RJ & L Carver College of Medicine in 1974. Dr. Johnson holds Iowa license 21505.
- NPI
- 1801848486NPI Registry (opens in a new tab)
- Medicare PAC ID
- 7214912401
- NPI enumeration date
- May 16, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (563) 584-4100
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 78
- Medical school graduation
- 1974
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Thomas Mark Johnson practices at Medical Associates Clinic P C in Dubuque, Iowa
Dr. Johnson's primary practice is Medical Associates Clinic P C, at 1000 Langworthy St, Dubuque, IA 52001 in Dubuque County. The practice phone is (563) 584-4100.
- Medical Associates Clinic P C1000 Langworthy St, Dubuque, IA 52001 · Dubuque CountyPhone(563) 584-4100
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Thomas Mark Johnson is affiliated with 4 sites of care and 1 medical group
Dr. Johnson's primary practice is Medical Associates Clinic P C in Dubuque, Iowa. Dr. Johnson is also affiliated with MercyOne Dubuque Medical Center. The medical group on file is Medical Associates Clinic. Dmand AI also links Dr. Johnson to 1 more hospital and 1 group practice or clinic, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Thomas Mark 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 |
|---|---|
| Medical Associates Clinic P C | Available with a free account |
| +3 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Thomas Mark Johnson is one of 166 cardiologists in Iowa
Cardiovascular disease is Dr. Johnson's primary specialty in the NPI Registry, under taxonomy code 207RC0000X. Dmand AI has Dr. Johnson's licenses on file in 2 states: Iowa and Wisconsin.
Specialties and state licenses
- Cardiovascular disease, IowaPrimary
- Wisconsin license
Cardiologists near Dr. Johnson
Counts of cardiologists 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. Thomas Mark Johnson billed Medicare for 896 services in 2024
CMS data shows 896 Medicare services from Dr. Johnson across 25 procedure codes in 2024, for 371 Medicare patients. Medicare paid $35,583 for them.
Dr. Johnson's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Tests and treatments
- 2023: 9602024: 50847%
- Office and hospital visits
- 2023: 4122024: 22545%
- Lab and pathology
- 2023: 2312024: 9758%
- Surgery
- 2023: 592024: 4524%
- Imaging
- 2023: 342024: 2138%
- Other services
- 2023: 542024: 0100%
Where Dr. Johnson's Medicare services took place, 2024
- In an office67776%
- In a facility21924%
Dr. Johnson compared with the Iowa median for cardiologists, 2024
- Dr. Johnson
- Iowa median
- Medicare services
- 896vs 1,59844% below
- Medicare patients
- 371vs 1,09466% below
- Part D claims
- 2,875vs 1,1382.5 times
Medians across 174 cardiologists in Iowa with Dmand AI profiles that report each measure.
Dr. Johnson's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Johnson and other cardiologists in Iowa.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Thomas Mark Johnson treated 371 Medicare patients in 2024, average age 78
CMS counts 371 Medicare patients who saw Dr. Johnson in 2024. The largest group is 75 to 84, with 148 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 13% are also on Medicaid. Their average risk score is 1.27, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Johnson's median patient age at 75, with 39% women.
Dr. Johnson's Medicare patients by age, 2024
Dr. Johnson's Medicare patients by sex, 2024
- Women16745%
- Men20455%
Chronic conditions among Dr. Johnson's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Ischemic heart disease48%
- Atrial fibrillation46%
- Arthritis38%
- Heart failure37%
- Chronic kidney disease36%
- Diabetes29%
Share of Medicare patients with each condition. A patient can have several.
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 75
Patient panel by sex, all payers
- Women39%
- Men60%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Thomas Mark Johnson wrote 2,993 Medicare Part D claims in 2024
In 2024, Dr. Johnson wrote 2,993 Medicare Part D claims for 438 patients. 80% of them were for generic drugs. CMS names the drug for 2,875 of them, across 30 drugs with 11 or more claims each, at $458,184 in total drug cost. In 2023, CMS named 3,435 claims across 33 drugs.
Dr. Johnson's Part D claims by kind of drug, 2024
- Generic2,408 claims80%
- Brand-name585 claims20%
Dr. Johnson'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. Johnson's Part D claims, 2024
- Antibiotics0%12 of 2,993 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: 3,4352024: 2,87516%
Drugs named by CMS: 30 in 2024, 33 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
How Dr. Thomas Mark Johnson takes part in Medicare
Dr. Johnson accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Coronary angioplasty and stenting: 1 to 10 procedures (CMS shows small counts as a range)
Pacemaker insertion or repair: 1 to 10 procedures (CMS shows small counts as a range)
Sources: Doctors and Clinicians National Downloadable File (CMS); and Doctors and Clinicians Utilization Data (CMS)
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Dr. Thomas Mark Johnson received $1,231 in industry payments from 2016 to 2025
CMS Open Payments shows 11 general payments to Dr. Johnson from 6 drug and device companies from 2016 to 2025. Travel and lodging make up the largest share, 78% of the total. Cardiovascular Systems Inc. paid the most, $1,101.
General payments to Dr. Johnson by program year, 2016 to 2025
General payments to Dr. Johnson by kind, 2016 to 2025
- Travel and lodging$96278%
- Food and beverage$26922%
Companies that paid Dr. Johnson the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Thomas Mark Johnson graduated from University of Iowa, RJ & L Carver College of Medicine
Dr. Johnson graduated from University of Iowa, RJ & L Carver College of Medicine in 1974.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Thomas Mark 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 | 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 DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| 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 | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (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. Thomas Mark 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. Thomas Mark Johnson's NPI number?
Dr. Thomas Mark Johnson's NPI number is 1801848486. It was assigned on May 16, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Thomas Mark Johnson?
Dr. Thomas Mark Johnson is a cardiologist in Dubuque, Iowa. The primary specialty in the NPI Registry is Cardiovascular Disease Physician (taxonomy code 207RC0000X).
Where does Dr. Thomas Mark Johnson practice?
Dr. Johnson practices at 1000 Langworthy St, Dubuque, IA 52001. Dr. Johnson's primary practice is Medical Associates Clinic P C in Dubuque, Iowa. Dmand AI also links Dr. Johnson to 1 hospital and 1 group practice or clinic.
What is Dr. Thomas Mark Johnson's office phone number?
The practice phone on file for Dr. Johnson is (563) 584-4100.
What is Dr. Thomas Mark Johnson's medical license number?
Dr. Johnson holds Iowa license 21505, one of the licenses on file in 2 states.
Which states has Dr. Thomas Mark Johnson been licensed in?
Dmand AI has state licenses on file for Dr. Johnson in Iowa and Wisconsin.
Which hospitals is Dr. Thomas Mark Johnson affiliated with?
Dr. Johnson is affiliated with MercyOne Dubuque Medical Center. Dmand AI links Dr. Johnson to 1 more hospital.
What medical group is Dr. Thomas Mark Johnson part of?
Dr. Johnson is linked to Medical Associates Clinic.
Does Dr. Thomas Mark Johnson accept Medicare?
Yes. CMS data shows Dr. Johnson billed Medicare for 896 services in 2024, and Dr. Johnson accepts Medicare assignment.
How many Medicare patients does Dr. Thomas Mark Johnson see?
CMS counts 371 Medicare patients who saw Dr. Johnson in 2024, with an average age of 78.
Show 5 more questionsShow fewer questions
What services does Dr. Thomas Mark Johnson bill to Medicare?
In 2024, Dr. Johnson's most billed Medicare services were office visit, established patient (99213), heart test or procedure (93296) and heart test or procedure (93294).
Where did Dr. Thomas Mark Johnson go to medical school?
Dr. Johnson graduated from University of Iowa, RJ & L Carver College of Medicine in 1974.
What drugs does Dr. Thomas Mark Johnson prescribe most?
In 2024 Medicare Part D data, Dr. Johnson's most prescribed drugs by claims were Metoprolol Succinate, Eliquis and Atorvastatin Calcium.
Has Dr. Thomas Mark Johnson received payments from drug or device companies?
CMS Open Payments shows $1,231 in general payments to Dr. Johnson from 6 companies from 2016 to 2025. The largest total came from Cardiovascular Systems Inc.
How long has Dr. Thomas Mark Johnson been practicing?
Dr. Johnson graduated from medical school in 1974, 52 years ago.
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