Mark Riley Jonker, M.D.
Internal Medicine Physician · Hartford, CT
Mark Riley Jonker, M.D. is an internal medicine physician with a practice address in Hartford, Connecticut, and NPI 1780030452, issued on May 11, 2016. Check the license (Connecticut 64205, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Mark Riley Jonker
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 64205 CT
Self-reported in NPPES; status is on the state search - Practice location
- 79 Retreat Avenue, Hartford, CT 06106
- Phone
- (860) 972-0200
- Enumerated
- May 11, 2016
- Record last updated
- Jun 3, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (860) 545-3149
- Medicare enrollment
- Enrolled (PECOS I20200611001504); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,623 in Connecticut → Look up another NPI →
Also registered at 79 Retreat Avenue
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Mark Riley Jonker in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 64205Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
93% fewer Medicare Part D claims than the average internal medicine physician in 2024
225 Medicare Part D claims for 101 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 12 claims were for opioids.
Most prescribed
- Prednisone21 claims
- Furosemide17 claims
- Divalproex Sodium Er15 claims
- Lactulose13 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The MIPS final score for 2023 (Medicare payment program): 97.3 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
One hospital affiliation
- Middlesex HospitalMiddletown, CT · Acute Care Hospitals3 of 5 stars
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
Mark Riley Jonker among 2,623 internal medicine physician records in Connecticut
Mark Riley Jonker, M.D. is one of 2,623 internal medicine physician records with a practice address in Connecticut. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2016, is newer than 77% of them.
- NPI issued2016 · 77% of these records are older, 20% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2016 · median 2004 among the 1,646 with a school on file
- Record last updated2020 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
169 internal medicine physician records list a practice address in Hartford
They are 169 of the 6,317 NPPES records with a practice address in Hartford, and 2,623 internal medicine physician records in Connecticut.
All 2,623 in Connecticut → Every provider in Hartford → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Samuel Anyatonwu, MDHartford, CT 061061023028933
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- Benjamin ChuHartford, CT 061061689848517
- Mary Colpoys, MDHartford, CT 061061104824275
- Aized Imtiaz, M.DHartford, CT 061061124212758
- Venkata Praveena Kota, MDHartford, CT 061061538362249
- William Laakso, MDHartford, CT 061061841399334
- Emilio Pandika, MDHartford, CT 061061851387518
Common questions
What is Mark Riley Jonker, M.D.'s NPI number?
Mark Riley Jonker, M.D.'s National Provider Identifier (NPI) is 1780030452, issued on May 11, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Mark Riley Jonker, M.D. located?
The NPPES record lists a practice address at 79 Retreat Avenue, Hartford, CT, 06106. Phone: (860) 972-0200. Providers update this record themselves, so call before visiting.
How can I verify Mark Riley Jonker, M.D.'s license?
NPPES lists Connecticut license number 64205, as entered by the provider. Search the Connecticut Medical Examining Board at https://www.elicense.ct.gov/Lookup/LicenseLookup.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark Riley Jonker, M.D. prescribe under Medicare Part D?
In 2024, Mark Riley Jonker, M.D. had 225 Medicare Part D claims for 101 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Mark Riley Jonker, M.D.'s MIPS final score?
The 2023 MIPS final score is 97.3 of 100. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.