NPPES file of Aug 9, 2026

Oscar Luis Alonso, M.D.

Specialist · Downers Grove, IL

Oscar Luis Alonso, M.D. is a specialist with a practice address in Downers Grove, Illinois, and NPI 1447285739, issued on Jul 12, 2006. Check the license (Illinois 036064967, as entered in NPPES) with the Illinois board that licenses this profession; 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
1447285739
Name
Oscar Luis Alonso
Credential
M.D.
Primary taxonomy
Specialist 174400000X
License number
036064967 IL
Self-reported in NPPES; status is on the state search
Practice location
1121 Warren Ave, Downers Grove, IL 60515
Phone
(630) 960-5310
Enumerated
Jul 12, 2006
Record last updated
Apr 16, 2021 (not updated in 5 years: call before relying on the address or phone)
Fax
(630) 969-7841
Medicaid ID
036064967 IL
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 1121 Warren Ave

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

  1. Robert LawlerObstetrics & Gynecology Physician1386758506
  2. Jillian Rawl Giammona, MA, LCPC, NCCProfessional Counselor1225319205
  3. Virginia Stack, M.S.; L.C.P.C.Mental Health Counselor1306954557
  4. Janice Walser, O.D.Optometrist1972649432
  5. Barbara Webster, DDSGeneral Practice Dentistry1710989876

Verify Oscar Luis Alonso in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Illinois board licenses this profession
    Search for license 036064967    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
Find the Illinois license search

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99% fewer Medicare Part D claims than the average specialist in 2024

17 Medicare Part D claims, against an average of 1,380 among the 8,233 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.

  1. Oscar Alonso17
  2. Specialty average1,380

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: $15.43

1 payment: food and beverage; the largest payer was Abbvie Inc. The 5,844 providers of this specialty with any payment received $4,760.79 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Oscar Alonso$15.43
  2. Specialty average$4,760.79

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

Specialist providers in Illinois

There are 1,154 specialist records in Illinois.

All 1,154 in Illinois → Every provider in Downers Grove →

Other specialist records in Illinois

  1. Sandra . Drewes, MDWinfield, IL1518056670
  2. Laketa AaronBellwood, IL1508508490
  3. Carrie Abbott-Walk, M.ED, DTDekalb, IL1841496171
  4. Babak Abdollahshamshirsaz, M.D.Chicago, IL1447585765
  5. Steven Abern, M.D.Park Ridge, IL1922027424
  6. Cherie AdamsEvanston, IL1063645810
  7. Robyn AdamsHerrin, IL1245216282
  8. Rita Agarwala, MDChicago, IL1972542991
  9. Ann Agustsson Mathers, D.O.Rockford, IL1417912411
  10. Nasir Ahmad, M.D.South Elgin, IL1447364526

Common questions

What is Oscar Luis Alonso, M.D.'s NPI number?

Oscar Luis Alonso, M.D.'s National Provider Identifier (NPI) is 1447285739, issued on Jul 12, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Oscar Luis Alonso, M.D. located?

The NPPES record lists a practice address at 1121 Warren Ave, Downers Grove, IL, 60515. Phone: (630) 960-5310. Providers update this record themselves, so call before visiting.

How can I verify Oscar Luis Alonso, M.D.'s license?

NPPES lists Illinois license number 036064967, as entered by the provider. Search the Illinois board that licenses this profession; the NPPES record confirms identity only.

How much does Oscar Luis Alonso, M.D. prescribe under Medicare Part D?

In 2024, Oscar Luis Alonso, M.D. had 17 Medicare Part D claims; the average among specialist prescribers was 1,380. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.