NPPES file of Aug 9, 2026

Colin Eash, DO

Internal Medicine Physician · Oak Lawn, IL

Colin Eash, DO is an internal medicine physician with a practice address in Oak Lawn, Illinois, and NPI 1811524390, issued on Mar 25, 2020. Check the license (Illinois 036161931, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; 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
1811524390
Name
Colin Eash
Credential
DO
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
036161931 IL
Self-reported in NPPES; status is on the state search
Practice location
4440 W 95TH St, Oak Lawn, IL 60453
Phone
(708) 684-5674
Enumerated
Mar 25, 2020
Record last updated
Sep 29, 2023
Fax
(708) 684-2500
Medicare enrollment
Enrolled (PECOS I20230814000708); accepts Medicare assignment
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 4440 W 95TH St

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

  1. Nadia Abdessalam, FNP-BCFamily Nurse Practitioner1356888283
  2. Akram Abdoue, M.D.Anesthesiology Physician1992752489
  3. Ahmad Abdulla, MDEmergency Medicine Physician1467202556
  4. Joseph Abraham, CRNACertified Registered Nurse Anesthetist1831653401
  5. Katherine Absalon, MOT, OTR/LOccupational Therapist1457753436
  6. Tassneem Abu-Rezeq, DNP, APRN, CPNP-ACPediatric Nurse Practitioner1831904663

Verify Colin Eash in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersIllinois Department of Financial and Professional Regulation
    Search for license 036161931
    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 Illinois 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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90% fewer Medicare Part D claims than the average internal medicine physician in 2024

329 Medicare Part D claims for 146 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 22 claims were for opioids.

  1. Colin Eash329
  2. Specialty average3,176

Most prescribed

  1. Amoxicillin-Clavulanate Potass25 claims
  2. Prednisone17 claims
  3. Eliquis14 claims
  4. Metoprolol Succinate14 claims
  5. Atorvastatin Calcium12 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

  1. Osf Multi-Specialty GroupRockford, IL

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

Colin Eash among 7,238 internal medicine physician records in Illinois

Colin Eash, DO 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 2020, is newer than 71% of them.

  • NPI issued2020 · 71% of these records are older, 26% newer
  • In a Medicare fileYes · 73% of these records are
  • In the CMS Doctors and Clinicians fileYes · 50% of these records are
  • Graduated2020 · median 2003 among the 3,580 with a school on file
  • Record last updated2023 · 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).

173 internal medicine physician records list a practice address in Oak Lawn

They are 173 of the 2,993 NPPES records with a practice address in Oak Lawn, and 7,238 internal medicine physician records in Illinois.

The 8 internal medicine physician records with the nearest ZIP codes

  1. Robert Chalupczak, M.D.Oak Lawn, IL 604531679505051
  2. Anupam Goel, MDOak Lawn, IL 604531013957570
  3. Joseph Kowalczyk, MDOak Lawn, IL 604531831166255
  4. Vinay Kumar, MDOak Lawn, IL 604531639138217
  5. Eugene Muzykansky, MDOak Lawn, IL 604531457328874
  6. Win Myint, MDOak Lawn, IL 604531063412062
  7. Robert Raines, MDOak Lawn, IL 604531164499596
  8. Mark Reiter, M.D.Oak Lawn, IL 604531902864408

Common questions

What is Colin Eash, DO's NPI number?

Colin Eash, DO's National Provider Identifier (NPI) is 1811524390, issued on Mar 25, 2020. An NPI identifies a provider in billing; it is not a license.

Where is Colin Eash, DO located?

The NPPES record lists a practice address at 4440 W 95TH St, Oak Lawn, IL, 60453. Phone: (708) 684-5674. Providers update this record themselves, so call before visiting.

How can I verify Colin Eash, DO's license?

NPPES lists Illinois license number 036161931, 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 Colin Eash, DO prescribe under Medicare Part D?

In 2024, Colin Eash, DO had 329 Medicare Part D claims for 146 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.