2026 NPPES data Internal Medicine Physician NPI 1497846091 MD
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CHARLA WILLIS, MD

Internal Medicine Physician in LEWISTON, Idaho. 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
10K
Medicare Part D claims · 760 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

CHARLA WILLIS, MD filed 9,731 Medicare Part D claims in 2023 as a Internal Medicine Physician in LEWISTON, Idaho, prescribing 89% generic.

10K
Part D claims, 2023
89%
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.

CHARLA WILLIS, MD's Medicare Part D volume vs every U.S. prescriber

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

9,731 Top 2% higher than 98% 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

Board-eligible specialty (heuristic — not verified)

CHARLA WILLIS, MD 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 CHARLA WILLIS, MD?

Quality data not reported

NPI registry status

Active

Issued 09/27/2006

NPI 1497846091

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

9,731 258% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Idaho

How Internal Medicine Physician compares to other specialties among Idaho providers

Idaho providers

Internal Medicine Physician share within Idaho

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within Idaho

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

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

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — 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).

CHARLA WILLIS, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 2315 8TH ST, LEWISTON, ID, 83501, with a listed phone of (208) 746-1383. NPI 1497846091 was issued on 09/27/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what WILLIS 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 9,731 prescription claims written by this provider, covering 760 Medicare beneficiaries and totaling roughly $719K in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 6.1%. 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.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

2315 8TH ST
LEWISTON, ID 83501

Provider Details

NPI 1497846091
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 09/27/2006

Brand vs generic prescribing mix · Typical

CHARLA WILLIS, MD — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 9,731 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.

9,731
Total Claims
$719K
Total Drug Cost
760
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
20,263
Total Day Supply
594,344
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$526K
Generic Drug Cost
$188K
Opioid Claims
592 (6.1% rate)
Antibiotic Claims
77

Patient Demographics

Average Patient Age
74.2 years
Avg HCC Risk Score
1.19
Gender Split
67% female / 33% male
Age Distribution
<65: 80, 65-74: 308, 75-84: 263, 85+: 109

Top Prescribed Drugs (Medicare Part D)

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

What CHARLA WILLIS, 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
Levothyroxine Sodium
600
Omeprazole
433
Atorvastatin Calcium
428
Amlodipine Besylate
331
Lisinopril
331
Losartan Potassium
291
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
238
Gabapentin
234
Metformin Hcl Er
Metformin Hcl
200
Simvastatin
181

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

Internal Medicine Physician Overview

How CHARLA WILLIS, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

CHARLA WILLIS, MD's 9,731 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Idaho

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

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is CHARLA WILLIS, MD's specialty?
CHARLA WILLIS, MD specializes in Internal Medicine Physician and practices in LEWISTON, Idaho. Credentials: MD.
How much does CHARLA WILLIS, MD prescribe under Medicare Part D?
In 2023, CHARLA WILLIS, MD wrote 9,731 Medicare Part D claims totaling $719K in drug costs for 760 beneficiaries.
Where is CHARLA WILLIS, MD located?
CHARLA WILLIS, MD is located at 2315 8TH ST, LEWISTON, ID, 83501. Phone: (208) 746-1383.
What is CHARLA WILLIS, MD's NPI number?
CHARLA WILLIS, MD's National Provider Identifier (NPI) is 1497846091, issued on 09/27/2006.
Does CHARLA WILLIS, MD prescribe more brand-name or generic drugs?
CHARLA WILLIS, MD's prescribing is 11% brand-name and 89% generic drugs by claim count, with $526K in brand drug costs.
Does CHARLA WILLIS, MD prescribe opioids?
Yes, CHARLA WILLIS, MD had 592 opioid claims in 2023 with an opioid prescribing rate of 6.1%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does CHARLA WILLIS, MD prescribe most often?
Based on 2023 Medicare Part D data, CHARLA WILLIS, MD's most frequently prescribed drugs include Levothyroxine Sodium, Omeprazole, Atorvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHARLA WILLIS, MD accept Medicare?
CHARLA WILLIS, MD appears in CMS Medicare data with 9,731 Part D claims and 760 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHARLA WILLIS, MD's credentials?
CHARLA WILLIS, MD's NPI is 1497846091 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