Registry data as of Aug 27, 2026

Don Williams, MD

Internal Medicine Physician · Oak Park, IL

Don Williams, MD is an internal medicine physician with a practice address in Oak Park, Illinois, and NPI 1447288287, issued on Jun 29, 2006. Check the license on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1447288287
Name
Don Williams
Credential
MD
Primary taxonomy
Internal Medicine Physician 207R00000X
Practice location
1100 Lake St Ste 230, Oak Park, IL 60301
Phone
(331) 221-9001
Enumerated
Jun 29, 2006
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 1100 Lake St Ste 230

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

  1. Ida Ahmady, DOFamily Medicine Physician1255081873
  2. Megan Helms, MDStudent in an Organized Health Care Education/Training Program1881344240
  3. Mary Hutton, MDFamily Medicine Physician1164415808
  4. Katherine Lynch, MDFamily Medicine Physician1821038720
  5. Elizabeth Mathew, MDFamily Medicine Physician1104389816
  6. Forrest Robinson, DOFamily Medicine Physician1740283803

Verify Don Williams in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersIllinois Department of Financial and Professional RegulationCheck 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.

76% more Medicare Part D claims than the average internal medicine physician in 2024

4,892 Medicare Part D claims for 335 beneficiaries, against an average of 2,785 among the 127,794 providers of this specialty who prescribed in Part D. 174 claims were for opioids.

  1. Don Williams4,892
  2. Specialty average2,785

Most prescribed

  1. Atorvastatin Calcium357 claims
  2. Pantoprazole Sodium174 claims
  3. Alprazolam164 claims
  4. Lisinopril151 claims
  5. Metformin Hcl151 claims
  6. Gabapentin144 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 Medicare quality score for 2023: 91.4 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.

  1. Qualityout of 100 · 30% of the final score82.7
  2. Costout of 100 · 30%
  3. Promoting interoperabilityout of 100 · 25%100.0
  4. Improvement activities40 of 40 points · 15%100.0

Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).

2 hospital and facility affiliations

  1. Dynamic Physical Therapy, Inc.Oak Park, IL
  2. Endeavor Health Medical GroupElmhurst, IL

Source: CMS Doctors and Clinicians affiliations; Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.

67 internal medicine physician records list a Oak Park practice address

They are 67 of the 2,307 NPPES records with a Oak Park practice address, and 8,522 internal medicine physician records in Illinois.

Other internal medicine physician records in Illinois

  1. Peter Abadeer, D.O.Bloomington, IL1760469522
  2. Pamela Abadi, D.O.Winfield, IL1588820179
  3. Motaz Abas, MDPeoria, IL1215510201
  4. Elias Abate, M.D.Chicago, IL1336712199
  5. Maliha Abbas, D.O.Chicago, IL1174963920
  6. Zareena Abbas, MDChicago, IL1427078872
  7. Abu Abbasi, MDChicago, IL1083243877
  8. Ayesha Abbasi, MDChicago, IL1376216705
  9. Khalda Abbasi, MDNaperville, IL1487705240
  10. Misha Abbasi, MDChicago, IL1770111635

Common questions

What is Don Williams, MD's NPI number?

Don Williams, MD's National Provider Identifier (NPI) is 1447288287, issued on Jun 29, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Don Williams, MD located?

The NPPES record lists a practice address at 1100 Lake St Ste 230, Oak Park, IL, 60301. Phone: (331) 221-9001. Providers update this record themselves, so call before visiting.

How can I verify Don Williams, MD's license?

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 Don Williams, MD prescribe under Medicare Part D?

In 2024, Don Williams, MD had 4,892 Medicare Part D claims for 335 beneficiaries; the average among internal medicine physician prescribers was 2,785. Part D covers Medicare prescriptions only.

What is Don Williams, MD's Medicare quality score?

The 2023 MIPS final score is 91.4 of 100. The average among 454,083 clinicians with a measured score was 83.5.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.