2026 NPPES data Optometrist NPI 1962574137 O.D.
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CHARLES ASSELL, O.D.

Optometrist in ST CHARLES, Illinois. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
184
Medicare Part D claims · 54 beneficiaries · Optometrist avg: 257
Generic prescribing
75%
generic claims · 25% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$618.55
22 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: CHARLES ASSELL, O.D. is a Optometrist ([object Object]) practicing in ST CHARLES, Illinois with a Medicare Part D prescribing footprint of 184 claims across 54 beneficiaries — 25% brand-name prescribing . Industry payments of $618.55 across 22 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: CHARLES ASSELL, O.D. filed 184 Medicare Part D claims in 2023 across ST CHARLES, Illinois. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

CHARLES ASSELL, O.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 11/14/2006

NPI 1962574137

Primary specialty

Optometrist

High-volume

60,463 US NPIs in this specialty

Medicare Part D claims

184 28% vs specialty avg

2023 prescription claims

Specialty avg: 257

Specialty distribution in Illinois

How Optometrist compares to other specialties among Illinois providers

Illinois providers

Optometrist share within Illinois

1. Optometrist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Optometrist share within Illinois

Specialty board-certification context

Estimated specialty board-certified rate — Optometrist (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Optometrist ABMS/AOA estimate

Est. board-certified rate (Optometrist) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Optometrist) — ABMS / AOA estimate

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).

CHARLES ASSELL, O.D. is a Optometrist provider practicing in ST CHARLES, Illinois, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: O.D.. NPI: 1962574137. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

CHARLES ASSELL, O.D. appears in the CMS NPPES registry as a Optometrist provider holding O.D. credentials at 3800 E MAIN ST, ST CHARLES, IL, 60174, with a listed phone of (630) 443-7200. NPI 1962574137 was issued on 11/14/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ASSELL most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 184 prescription claims written by this provider, covering 54 Medicare beneficiaries and totaling roughly $20K in drug spend, split 25% brand-name and 75% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Optometrist is a high-volume specialty nationwide, with 60,463 enrolled providers across 56 states and an average of 257 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

3800 E MAIN ST
ST CHARLES, IL 60174

Provider Details

NPI 1962574137
Specialty Optometrist
Credentials O.D.
Gender Male
NPI Issued 11/14/2006

Hospital and facility affiliations

Facilities where CHARLES ASSELL, O.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

DRS. AIDE AND ASSELL OPTOMETRISTS, P.C.
HOFFMAN ESTATES, IL

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for CHARLES ASSELL, O.D.. Source: openpaymentsdata.cms.gov.

Total received

$619

Largest payer

Alcon Vision LLC

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

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 CHARLES ASSELL, O.D.. To verify CHARLES ASSELL, O.D.'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 · Above average

CHARLES ASSELL, O.D. — brand share 25.0%
Specialty average (est.)

25% brand-name claims vs 75% generic, on 184 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.

184
Total Claims
$20K
Total Drug Cost
54
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
289
Total Day Supply
7,550
Brand vs Generic
25% brand / 75% generic
Brand Drug Cost
$13K
Generic Drug Cost
$7K

Patient Demographics

Average Patient Age
73.7 years
Avg HCC Risk Score
0.88
Gender Split
56% female / 44% male

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Latanoprost
56
Brimonidine Tartrate
27
Tobramycin-Dexamethasone
Tobramycin/Dexamethasone
11

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Optometrist Overview

How CHARLES ASSELL, O.D. fits within the Optometrist landscape nationally.

60,463
Optometrist Providers in US
56
States with Optometrist
257
Avg Claims per Provider

CHARLES ASSELL, O.D.'s 184 claims are below the specialty average of 257.

Nearby Optometrist Providers in Illinois

Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as ASSELL.

Compare Optometrist nationally: see state-by-state distribution →

Frequently Asked Questions

What is CHARLES ASSELL, O.D.'s specialty?
CHARLES ASSELL, O.D. specializes in Optometrist and practices in ST CHARLES, Illinois. Credentials: O.D..
How much does CHARLES ASSELL, O.D. prescribe under Medicare Part D?
In 2023, CHARLES ASSELL, O.D. wrote 184 Medicare Part D claims totaling $20K in drug costs for 54 beneficiaries.
Where is CHARLES ASSELL, O.D. located?
CHARLES ASSELL, O.D. is located at 3800 E MAIN ST, ST CHARLES, IL, 60174. Phone: (630) 443-7200.
What is CHARLES ASSELL, O.D.'s NPI number?
CHARLES ASSELL, O.D.'s National Provider Identifier (NPI) is 1962574137, issued on 11/14/2006.
Does CHARLES ASSELL, O.D. prescribe more brand-name or generic drugs?
CHARLES ASSELL, O.D.'s prescribing is 25% brand-name and 75% generic drugs by claim count, with $13K in brand drug costs.
How many Optometrist providers are there in the US?
There are 60,463 Optometrist providers across 56 states in the US. The average Optometrist provider writes 257 Medicare Part D claims per year.
What drugs does CHARLES ASSELL, O.D. prescribe most often?
Based on 2023 Medicare Part D data, CHARLES ASSELL, O.D.'s most frequently prescribed drugs include Latanoprost, Brimonidine Tartrate, Tobramycin-Dexamethasone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHARLES ASSELL, O.D. accept Medicare?
CHARLES ASSELL, O.D. appears in CMS Medicare data with 184 Part D claims and 54 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHARLES ASSELL, O.D.'s credentials?
CHARLES ASSELL, O.D.'s NPI is 1962574137 with credentials O.D.. 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

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