2026 NPPES data Specialist NPI 1811996028 MD
Verify on CMS →

CHARLES WILLEY, MD

Specialist in SAINT LOUIS, Missouri. 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
7K
Medicare Part D claims · 870 beneficiaries · Specialist avg: 1K
Generic prescribing
93%
generic claims · 7% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$125
1 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

CHARLES WILLEY, MD filed 7,362 Medicare Part D claims in 2023 as a Specialist in SAINT LOUIS, Missouri, prescribing 93% generic.

7K
Part D claims, 2023
93%
generic prescribing
$125
industry payments (Sunshine Act)

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.

CHARLES WILLEY, MD's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

7,362 Top 3% higher than 97% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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

What does the federal data show about CHARLES WILLEY, MD?

Quality data not reported

NPI registry status

Active

Issued 07/19/2005

NPI 1811996028

Primary specialty

Specialist

High-volume

69,658 US NPIs in this specialty

Medicare Part D claims

7,362 399% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

Specialty distribution in Missouri

How Specialist compares to other specialties among Missouri providers

Missouri providers

Specialist share within Missouri

1. Specialist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Specialist share within Missouri

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Specialist) — 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 WILLEY, MD appears in the CMS NPPES registry as a Specialist provider holding MD credentials at 9915 KENNERLY RD, SAINT LOUIS, MO, 63128, with a listed phone of (314) 843-4794. NPI 1811996028 was issued on 07/19/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what WILLEY 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 7,362 prescription claims written by this provider, covering 870 Medicare beneficiaries and totaling roughly $387K in drug spend, split 7% brand-name and 93% generic by claim count, with an opioid prescribing rate of 3.1%. 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.

Specialist is a high-volume specialty nationwide, with 69,658 enrolled providers across 55 states and an average of 1,474 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

9915 KENNERLY RD
SAINT LOUIS, MO 63128

Provider Details

NPI 1811996028
Specialty Specialist
Credentials MD
Gender Male
NPI Issued 07/19/2005

Hospital and facility affiliations

Facilities where CHARLES WILLEY, MD 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.

AGING WELL HEALTH CARE, LLC
SAINT LOUIS, MO
CJW ENTERPRISES, INC
SAINT LOUIS, MO

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 WILLEY, MD. Source: openpaymentsdata.cms.gov.

Total received

$125

Largest payer

Sumitomo Pharma America, Inc.

Most common payment type

Compensation for services other than consulting, including serving as faculty or as a speaker at a venue other than a continuing education program

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.

Brand vs generic prescribing mix · Generic-heavy

CHARLES WILLEY, MD — brand share 7.0%
Specialty average (est.)

7% brand-name claims vs 93% generic, on 7,362 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.

7,362
Total Claims
$387K
Total Drug Cost
870
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
14,495
Total Day Supply
415,428
Brand vs Generic
7% brand / 93% generic
Brand Drug Cost
$246K
Generic Drug Cost
$138K
Opioid Claims
227 (3.1% rate)
Antibiotic Claims
246

Patient Demographics

Average Patient Age
78.7 years
Avg HCC Risk Score
1.55
Gender Split
52% female / 48% male
Age Distribution
<65: 22, 65-74: 260, 75-84: 385, 85+: 203

Top Prescribed Drugs (Medicare Part D)

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

What CHARLES WILLEY, MD prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
352
Mirtazapine
262
Lisinopril
222
Losartan Potassium
199
Eliquis
Apixaban
185
Amlodipine Besylate
184
Levothyroxine Sodium
182
Metoprolol Tartrate
181
Quetiapine Fumarate
180
Alprazolam
179

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

Specialist Overview

How CHARLES WILLEY, MD fits within the Specialist landscape nationally.

69,658
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider

CHARLES WILLEY, MD's 7,362 claims are above the specialty average of 1,474.

Nearby Specialist Providers in Missouri

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

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

Frequently Asked Questions

What is CHARLES WILLEY, MD's specialty?
CHARLES WILLEY, MD specializes in Specialist and practices in SAINT LOUIS, Missouri. Credentials: MD.
How much does CHARLES WILLEY, MD prescribe under Medicare Part D?
In 2023, CHARLES WILLEY, MD wrote 7,362 Medicare Part D claims totaling $387K in drug costs for 870 beneficiaries.
Where is CHARLES WILLEY, MD located?
CHARLES WILLEY, MD is located at 9915 KENNERLY RD, SAINT LOUIS, MO, 63128. Phone: (314) 843-4794.
What is CHARLES WILLEY, MD's NPI number?
CHARLES WILLEY, MD's National Provider Identifier (NPI) is 1811996028, issued on 07/19/2005.
Does CHARLES WILLEY, MD prescribe more brand-name or generic drugs?
CHARLES WILLEY, MD's prescribing is 7% brand-name and 93% generic drugs by claim count, with $246K in brand drug costs.
Does CHARLES WILLEY, MD prescribe opioids?
Yes, CHARLES WILLEY, MD had 227 opioid claims in 2023 with an opioid prescribing rate of 3.1%.
How many Specialist providers are there in the US?
There are 69,658 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does CHARLES WILLEY, MD prescribe most often?
Based on 2023 Medicare Part D data, CHARLES WILLEY, MD's most frequently prescribed drugs include Atorvastatin Calcium, Mirtazapine, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHARLES WILLEY, MD accept Medicare?
CHARLES WILLEY, MD appears in CMS Medicare data with 7,362 Part D claims and 870 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHARLES WILLEY, MD's credentials?
CHARLES WILLEY, MD's NPI is 1811996028 with credentials MD. 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