Catherine J. Koop, M.D.
Internal Medicine Physician · Oak Park, IL
Catherine J. Koop, M.D. is an internal medicine physician with a practice address in Oak Park, Illinois, and NPI 1851358972, issued on May 1, 2006. Check the license (Illinois 036-096959, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Catherine J. Koop
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 036-096959 IL
036096959 IL
Self-reported in NPPES; status is on the state search - Practice location
- 610 S. Maple, Oak Park, IL 60304
- Phone
- (708) 660-2240
- Enumerated
- May 1, 2006
- Record last updated
- Jul 21, 2022
- Fax
- (708) 660-2243
- Medicaid ID
- 036096959 IL
- Medicare enrollment
- Enrolled (PECOS I20100617000026); accepts Medicare assignment
- Medical or professional school
- Rush Medical College Of Rush University, 1995
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 7,238 in Illinois → Look up another NPI →
Verify Catherine J. Koop in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIllinois Department of Financial and Professional Regulation
Search for license 036-096959Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
13% more Medicare Part D claims than the average internal medicine physician in 2024
3,603 Medicare Part D claims for 366 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 108 claims were for opioids.
Most prescribed
- Atorvastatin Calcium217 claims
- Amlodipine Besylate209 claims
- Levothyroxine Sodium175 claims
- Simvastatin128 claims
- Escitalopram Oxalate104 claims
- Hydrochlorothiazide98 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.
Bills Medicare through one group practice
- Rush Oak Park Physicians Group Adult MedicineOak Park, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Catherine J. Koop among 7,238 internal medicine physician records in Illinois
Catherine J. Koop, M.D. is one of 7,238 internal medicine physician records with a practice address in Illinois. 73% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 61% newer
- In a Medicare fileYes · 73% of these records are
- In the CMS Doctors and Clinicians fileYes · 50% of these records are
- Graduated1995 · median 2003 among the 3,580 with a school on file
- Record last updated2022 · 47% 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 Illinois practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
62 internal medicine physician records list a practice address in Oak Park
They are 62 of the 2,307 NPPES records with a practice address in Oak Park, and 7,238 internal medicine physician records in Illinois.
All 7,238 in Illinois → Every provider in Oak Park → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sheba Chiplunkar, M.D.Oak Park, IL 603041356374656
- Bernard Coniglio, M.D.Oak Park, IL 603041124085568
- Marie Feldman, MDOak Park, IL 603041841386729
- Janet Forbes, M.D.Oak Park, IL 603041295838779
- Catalina Grija, M.D.Oak Park, IL 603041770793143
- Rita Gupta, M.D.Oak Park, IL 603041922117985
- Mohammad Khan, M.D.Oak Park, IL 603041487653838
- James Miller, M.D.Oak Park, IL 603041730298886
Common questions
What is Catherine J. Koop, M.D.'s NPI number?
Catherine J. Koop, M.D.'s National Provider Identifier (NPI) is 1851358972, issued on May 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Catherine J. Koop, M.D. located?
The NPPES record lists a practice address at 610 S. Maple, Oak Park, IL, 60304. Phone: (708) 660-2240. Providers update this record themselves, so call before visiting.
How can I verify Catherine J. Koop, M.D.'s license?
NPPES lists Illinois license number 036-096959, as entered by the provider. Search the Illinois Department of Financial and Professional Regulation at https://idfpr.illinois.gov/checklicense.html. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Catherine J. Koop, M.D. prescribe under Medicare Part D?
In 2024, Catherine J. Koop, M.D. had 3,603 Medicare Part D claims for 366 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.