NPPES file of Aug 9, 2026

Ian D. Kleinhen, M.D.

Internal Medicine Physician · Windsor, CT

Ian D. Kleinhen, M.D. is an internal medicine physician with a practice address in Windsor, Connecticut, and NPI 1013916808, issued on Jul 14, 2005. Check the license (Connecticut 036853, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1013916808
Name
Ian D. Kleinhen
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
036853 CT
Self-reported in NPPES; status is on the state search
Practice location
74 Mack St, Windsor, CT 06095
Phone
(860) 298-8830
Enumerated
Jul 14, 2005
Record last updated
Feb 27, 2020 (not updated in 6 years: call before relying on the address or phone)
Fax
(860) 298-9929
Medicaid ID
001368530 CT
Medicare enrollment
Enrolled (PECOS I20051209000199); accepts Medicare assignment
Medical or professional school
Georgetown University School Of Medicine, 1995
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 74 Mack St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Shahena Master, D.O.Internal Medicine Physician1174522973
  2. Joseph Misiak, M.D.Internal Medicine Physician1871592667
  3. Kay PattersonRegistered Nurse1962371278
  4. Mahammed Saiyed, M.DFamily Medicine Physician1326253469
  5. David Sherwood, M.D.Internal Medicine Physician1508865387

Verify Ian D. Kleinhen in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersConnecticut Medical Examining Board
    Search for license 036853
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Connecticut license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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22% more Medicare Part D claims than the average internal medicine physician in 2024

3,862 Medicare Part D claims for 231 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 13% of claims. 50 claims were for opioids.

  1. Ian Kleinhen3,862
  2. Specialty average3,176

Most prescribed

  1. Rosuvastatin Calcium389 claims
  2. Levothyroxine Sodium206 claims
  3. Amlodipine Besylate172 claims
  4. Atorvastatin Calcium163 claims
  5. Lisinopril116 claims
  6. Metformin Hcl115 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.

Industry payments in 2024: $461.60

12 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Ian Kleinhen$461.60
  2. Specialty average$1,303.06

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through 2 group practices

  1. Mclean FundSimsbury, CT
  2. Ptsma IncPawcatuck, CT

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Ian D. Kleinhen among 2,623 internal medicine physician records in Connecticut

Ian D. Kleinhen, 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 2005, is newer than 0% of them.

  • NPI issued2005 · 0% of these records are older, 89% newer
  • In a Medicare fileYes · 81% of these records are
  • In the CMS Doctors and Clinicians fileYes · 63% of these records are
  • Graduated1995 · 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).

9 internal medicine physician records list a practice address in Windsor

They are 9 of the 884 NPPES records with a practice address in Windsor, and 2,623 internal medicine physician records in Connecticut.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Muzibul Chowdhury, M.D.Windsor, CT 060951093730012
  2. Jeffrey Davies, M.D.Windsor, CT 060951396874723
  3. Joan Gigstad, MDWindsor, CT 060951396711222
  4. Shahena Master, D.O.Windsor, CT 060951174522973
  5. Joseph Misiak, M.D.Windsor, CT 060951871592667
  6. Christine Najjar, MD, MS, MHP, ABOMWindsor, CT 060951407210016
  7. Elizabeth Schuck, MDWindsor, CT 060951144207655
  8. David Sherwood, M.D.Windsor, CT 060951508865387

Common questions

What is Ian D. Kleinhen, M.D.'s NPI number?

Ian D. Kleinhen, M.D.'s National Provider Identifier (NPI) is 1013916808, issued on Jul 14, 2005. An NPI identifies a provider in billing; it is not a license.

Where is Ian D. Kleinhen, M.D. located?

The NPPES record lists a practice address at 74 Mack St, Windsor, CT, 06095. Phone: (860) 298-8830. Providers update this record themselves, so call before visiting.

How can I verify Ian D. Kleinhen, M.D.'s license?

NPPES lists Connecticut license number 036853, 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 Ian D. Kleinhen, M.D. prescribe under Medicare Part D?

In 2024, Ian D. Kleinhen, M.D. had 3,862 Medicare Part D claims for 231 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.

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.