NPI registry status
Active
2026 NPPES data Family Medicine Physician NPI 1821521238 D.O.
Verify on CMS → Weslin Thomas, D.O.
Family Medicine Physician in Des Plaines, Illinois.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 147,760 in Family Medicine Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
76K
Medicare Part D claims · 67K beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
2%
generic claims · 98% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Weslin Thomas, D.O. filed 75,589 Medicare Part D claims in 2023 as a Family Medicine Physician in Des Plaines, Illinois, prescribing 2% generic.
- 76K
- Part D claims, 2023
- 2%
- generic prescribing
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Weslin Thomas, D.O.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
75,589 Top 2% higher than 98% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
Weslin Thomas, D.O. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Weslin Thomas, D.O.?
Quality data not reportedPrimary specialty
Family Medicine Physician
Medicare Part D claims
75,589 22× vs specialty avg
Specialty distribution in Illinois
How Family Medicine Physician compares to other specialties among Illinois providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Family Medicine Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Weslin Thomas, D.O. appears in the CMS NPPES registry as a Family Medicine Physician provider holding D.O. credentials at 77 RAND RD, Des Plaines, IL, 60016, with a listed phone of (847) 825-0300. NPI 1821521238 was issued on 04/04/2017.
Medicare Part D records for calendar year 2023 show 75,589 prescription claims written by this provider, covering 66,656 Medicare beneficiaries and totaling roughly $20.0 million in drug spend, split 98% brand-name and 2% generic by claim count.
Family Medicine Physician is a high-volume specialty nationwide, with 147,760 enrolled providers across 56 states and an average of 3,418 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1821521238 |
|---|---|
| Specialty | Family Medicine Physician |
| Credentials | D.O. |
| Gender | Male |
| NPI Issued | 04/04/2017 |
License & disciplinary context - Illinois IDFPR 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~42K Illinois medical licensees in 2023 - they are NOT specific to Weslin Thomas, D.O.. To verify Weslin Thomas, D.O.'s current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases
IDFPR publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Brand-heavy
Weslin Thomas, D.O. - brand share 98.0%
Family Medicine Physician average
98% brand-name claims vs 2% generic, on 75,589 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
75,589
Total Claims
$20.0M
Total Drug Cost
66,656
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 75,695
- Total Day Supply
- 83,532
- Brand vs Generic
- 98% brand / 2% generic
- Brand Drug Cost
- $19.9M
- Generic Drug Cost
- $129K
Patient Demographics
- Average Patient Age
- 73.1 years
- Avg HCC Risk Score
- 1.17
- Gender Split
- 58% female / 42% male
- Age Distribution
- <65: 4,088, 65-74: 36,200, 75-84: 21,916, 85+: 4,452
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Weslin Thomas, D.O. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Arexvy
Arexvy
41,580 claims
- Shingrix
Shingrix
20,272 claims
- Twinrix 3,428
Twinrix
3,428 claims
- Naloxone Hcl 1,679
Naloxone Hcl
1,679 claims
- Havrix 116
Havrix
116 claims
- Gardasil 9 50
Gardasil 9
50 claims
- Vaqta 46
Vaqta
46 claims
- Narcan 30
Narcan
30 claims
| Drug | Claims |
|---|---|
| Arexvy Rsvpref3 Antigen/As01e/Pf | 41,580 |
| Shingrix Varicella-Zoster Ge/As01b/Pf | 20,272 |
| Twinrix Hepatitis A And B Vaccine/Pf | 3,428 |
| Naloxone Hcl | 1,679 |
| Havrix Hepatitis A Virus Vaccine/Pf | 116 |
| Gardasil 9 Hpv Vaccine 9-Valent/Pf | 50 |
| Vaqta Hepatitis A Virus Vaccine/Pf | 46 |
| Narcan Naloxone Hcl | 30 |
| Atorvastatin Calcium | 13 |
| Amlodipine Besylate | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Family Medicine Physician Overview
How Weslin Thomas, D.O. fits within the Family Medicine Physician landscape nationally.
147,760
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider
Weslin Thomas, D.O.'s 75,589 claims are above the specialty average of 3,418.
Nearby Family Medicine Physician Providers in Illinois
Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as Thomas.
Dr. Jon Aagaard
MD
Wheaton, IL
Dr. Napoleon Abando
MD
Woodstock, IL
Dr. Nikka Abaricia
MD
Chicago, IL
Mohemmed Abbas
Chicago, IL
Muhammad Abbas
Alton, IL
Compare Family Medicine Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Illinois medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Family Medicine Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Weslin Thomas, D.O.'s specialty? ▼
Weslin Thomas, D.O. specializes in Family Medicine Physician and practices in Des Plaines, Illinois. Credentials: D.O..
How much does Weslin Thomas, D.O. prescribe under Medicare Part D? ▼
In 2023, Weslin Thomas, D.O. wrote 75,589 Medicare Part D claims totaling $20.0M in drug costs for 66,656 beneficiaries.
Where is Weslin Thomas, D.O. located? ▼
Weslin Thomas, D.O. is located at 77 RAND RD, Des Plaines, IL, 60016. Phone: (847) 825-0300.
What is Weslin Thomas, D.O.'s NPI number? ▼
Weslin Thomas, D.O.'s National Provider Identifier (NPI) is 1821521238, issued on 04/04/2017.
Does Weslin Thomas, D.O. prescribe more brand-name or generic drugs? ▼
Weslin Thomas, D.O.'s prescribing is 98% brand-name and 2% generic drugs by claim count, with $19.9M in brand drug costs.
How many Family Medicine Physician providers are there in the US? ▼
There are 147,760 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does Weslin Thomas, D.O. prescribe most often? ▼
Based on 2023 Medicare Part D data, Weslin Thomas, D.O.'s most frequently prescribed drugs include Arexvy, Shingrix, Twinrix. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Weslin Thomas, D.O. accept Medicare? ▼
Weslin Thomas, D.O. appears in CMS Medicare data with 75,589 Part D claims and 66,656 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Weslin Thomas, D.O.'s credentials? ▼
Weslin Thomas, D.O.'s NPI is 1821521238 with credentials D.O.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.
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 May 2026.