Allen D. Williams, MD
Internal Medicine Physician · Rockford, IL
Allen D. Williams, MD is an internal medicine physician with a practice address in Rockford, Illinois, and NPI 1073601324, issued on Oct 11, 2006. Check the license (Illinois 036103011, as entered in NPPES) on the Illinois Department of Financial and Professional Regulation; the Medicare figures below come from public CMS files.
- Name
- Allen D. Williams
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 036103011 IL
Self-reported in NPPES; status is on the state search - Practice location
- 3505 N. Bell School RD., Rockford, IL 61114
- Phone
- (779) 696-0300
- Enumerated
- Oct 11, 2006
- Record last updated
- Feb 18, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicaid ID
- 036103011 IL
- Medicare enrollment
- Enrolled (PECOS I20100123000174); accepts Medicare assignment
- Medical or professional school
- Loyola University Of Chicago, Stritch School Of Medicine, 1998
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 7,238 in Illinois → Look up another NPI →
Also registered at 3505 N. Bell School RD.
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Lee Sesslar, MDObstetrics & Gynecology Physician1073511689
- Srivani Sridhar, MDFamily Medicine Physician1003075318
Verify Allen D. Williams 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 036103011Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4.2 times the Medicare Part D claims of the average internal medicine physician in 2024
13,438 Medicare Part D claims for 905 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 153 claims were for opioids.
Most prescribed
- Atorvastatin Calcium1,093 claims
- Amlodipine Besylate640 claims
- Levothyroxine Sodium594 claims
- Losartan Potassium398 claims
- Lisinopril354 claims
- Metformin Hcl344 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 practice group's MIPS final score for 2023 (Medicare payment program): 75 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through 2 group practices
- Select Rehabilitation, LLCGlenview, IL
- Swedishamerican HospitalByron, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Allen D. Williams among 7,238 internal medicine physician records in Illinois
Allen D. Williams, MD 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
- Graduated1998 · median 2003 among the 3,580 with a school on file
- Record last updated2021 · 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).
82 internal medicine physician records list a practice address in Rockford
They are 82 of the 3,893 NPPES records with a practice address in Rockford, and 7,238 internal medicine physician records in Illinois.
All 7,238 in Illinois → Every provider in Rockford → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Humaira Bari, MDRockford, IL 611141497845135
- Thomas Brefeld, MDRockford, IL 611141699885871
- Daniel Chamberlain, MDRockford, IL 611141396833307
- Aaron Coates, MDRockford, IL 611141871603050
- Venkata Dontaraju, M.D, MRCPRockford, IL 611141821241084
- Daniel Herdeman, MDRockford, IL 611141447293451
- Willard Moore, MDRockford, IL 611141831209022
- Peter Phelan, MDRockford, IL 611141548358534
Common questions
What is Allen D. Williams, MD's NPI number?
Allen D. Williams, MD's National Provider Identifier (NPI) is 1073601324, issued on Oct 11, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Allen D. Williams, MD located?
The NPPES record lists a practice address at 3505 N. Bell School RD., Rockford, IL, 61114. Phone: (779) 696-0300. Providers update this record themselves, so call before visiting.
How can I verify Allen D. Williams, MD's license?
NPPES lists Illinois license number 036103011, 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 Allen D. Williams, MD prescribe under Medicare Part D?
In 2024, Allen D. Williams, MD had 13,438 Medicare Part D claims for 905 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Allen D. Williams, MD's MIPS final score?
The 2023 MIPS final score is 75 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.