2026 NPPES data Internal Medicine Physician NPI 1104131820 MD
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WILLIAM NASSOUR, MD

Internal Medicine Physician in GOODYEAR, Arizona. 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
27K
Medicare Part D claims · 1K beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
85%
generic claims · 15% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$584.89
30 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WILLIAM NASSOUR, MD filed 26,771 Medicare Part D claims in 2023 as a Internal Medicine Physician in GOODYEAR, Arizona, prescribing 85% generic.

27K
Part D claims, 2023
85%
generic prescribing
Likely
board-certified (heuristic)

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.

WILLIAM NASSOUR, MD's Medicare Part D volume vs every U.S. prescriber

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

26,771 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 certification likely (heuristic — not verified)

WILLIAM NASSOUR, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 3 hospital affiliations — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about WILLIAM NASSOUR, MD?

Quality data not reported

NPI registry status

Active

Issued 08/18/2010

NPI 1104131820

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

26,771 886% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Arizona

How Internal Medicine Physician compares to other specialties among Arizona providers

Arizona providers

Internal Medicine Physician share within Arizona

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

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).

WILLIAM NASSOUR, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 13555 W MCDOWELL RD STE 205, GOODYEAR, AZ, 85395, with a listed phone of (623) 295-1190. NPI 1104131820 was issued on 08/18/2010. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what NASSOUR 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 26,771 prescription claims written by this provider, covering 1,169 Medicare beneficiaries and totaling roughly $2.4 million in drug spend, split 15% brand-name and 85% generic by claim count, with an opioid prescribing rate of 0.2%. 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

13555 W MCDOWELL RD STE 205
GOODYEAR, AZ 85395

Provider Details

NPI 1104131820
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 08/18/2010

Hospital and facility affiliations

Facilities where WILLIAM NASSOUR, 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.

DESERT WOUNDS PLLC
PHOENIX, AZ
LEADING HEALTHCARE CLINIC OF GOODYEAR, LLC
GOODYEAR, AZ
LEADING HEALTHCARE PLLC
SURPRISE, AZ

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 WILLIAM NASSOUR, MD. Source: openpaymentsdata.cms.gov.

Total received

$585

Largest payer

UCB, Inc.

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.

Brand vs generic prescribing mix · Typical

WILLIAM NASSOUR, MD — brand share 15.0%
Specialty average (est.)

15% brand-name claims vs 85% generic, on 26,771 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.

26,771
Total Claims
$2.4M
Total Drug Cost
1,169
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
27,313
Total Day Supply
643,071
Brand vs Generic
15% brand / 85% generic
Brand Drug Cost
$1.6M
Generic Drug Cost
$833K
Opioid Claims
52 (0.2% rate)
Antibiotic Claims
645

Patient Demographics

Average Patient Age
72.3 years
Avg HCC Risk Score
3.39
Gender Split
51% female / 49% male
Age Distribution
<65: 240, 65-74: 411, 75-84: 341, 85+: 177

Top Prescribed Drugs (Medicare Part D)

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

What WILLIAM NASSOUR, 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
1,488
Gabapentin
1,080
Levothyroxine Sodium
870
Eliquis
Apixaban
856
Amlodipine Besylate
714
Trazodone Hcl
622
Furosemide
610
Tamsulosin Hcl
597
Metformin Hcl
580
Metoprolol Tartrate
579

* 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 WILLIAM NASSOUR, 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

WILLIAM NASSOUR, MD's 26,771 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Arizona

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

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

Frequently Asked Questions

What is WILLIAM NASSOUR, MD's specialty?
WILLIAM NASSOUR, MD specializes in Internal Medicine Physician and practices in GOODYEAR, Arizona. Credentials: MD.
How much does WILLIAM NASSOUR, MD prescribe under Medicare Part D?
In 2023, WILLIAM NASSOUR, MD wrote 26,771 Medicare Part D claims totaling $2.4M in drug costs for 1,169 beneficiaries.
Where is WILLIAM NASSOUR, MD located?
WILLIAM NASSOUR, MD is located at 13555 W MCDOWELL RD STE 205, GOODYEAR, AZ, 85395. Phone: (623) 295-1190.
What is WILLIAM NASSOUR, MD's NPI number?
WILLIAM NASSOUR, MD's National Provider Identifier (NPI) is 1104131820, issued on 08/18/2010.
Does WILLIAM NASSOUR, MD prescribe more brand-name or generic drugs?
WILLIAM NASSOUR, MD's prescribing is 15% brand-name and 85% generic drugs by claim count, with $1.6M in brand drug costs.
Does WILLIAM NASSOUR, MD prescribe opioids?
Yes, WILLIAM NASSOUR, MD had 52 opioid claims in 2023 with an opioid prescribing rate of 0.2%.
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 WILLIAM NASSOUR, MD prescribe most often?
Based on 2023 Medicare Part D data, WILLIAM NASSOUR, MD's most frequently prescribed drugs include Atorvastatin Calcium, Gabapentin, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WILLIAM NASSOUR, MD accept Medicare?
WILLIAM NASSOUR, MD appears in CMS Medicare data with 26,771 Part D claims and 1,169 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WILLIAM NASSOUR, MD's credentials?
WILLIAM NASSOUR, MD's NPI is 1104131820 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