NPI registry status
Active
2026 NPPES data Addiction Medicine (Preventive Medicine) Physician NPI 1427542927
Verify on CMS → William Fox Jr
Addiction Medicine (Preventive Medicine) Physician in Litchfield Park, Arizona.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 343 in Addiction Medicine (Preventive 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
206
Medicare Part D claims · 24 beneficiaries · Addiction Medicine (Preventive Medicine) Physician avg: 929
Generic prescribing
90%
generic claims · 10% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
William Fox Jr filed 206 Medicare Part D claims in 2024 as an Addiction Medicine (Preventive Medicine) Physician in Litchfield Park, Arizona, prescribing 90% generic.
- 206
- Part D claims, 2024
- 90%
- generic prescribing
- ≥48th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about William Fox Jr
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1427542927), first enumerated 06/18/2018.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 206 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Practices in an ABMS-board-eligible specialty; board certification not confirmed in federal records.
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1427542927 · Addiction Medicine (Preventive Medicine) Physician
NPI-10 · ENUM-RECENT · TAX-TRACE · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1427542927
- ENUM-RECENT 2018
- TAX-TRACE 343
- RX-LIGHT 206
- BOOK-THIN 9 in Arizona
- PHOTO-ENUM Timothy Ibrahim · 2018
William Fox Jr's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
206 ≥ 48th percentile 48% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
◑
Board-eligible specialty (heuristic, not verified)
William Fox Jr 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 William Fox Jr?
Quality data not reportedPrimary specialty
Addiction Medicine (Preventive Medicine) Physician
Medicare Part D claims
206 78% vs specialty avg
Specialty distribution in Arizona
How Addiction Medicine (Preventive Medicine) Physician compares to other specialties among Arizona 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 Addiction Medicine (Preventive 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).
Practice Address
Provider Details
| NPI | 1427542927 |
|---|---|
| Specialty | Addiction Medicine (Preventive Medicine) Physician |
| Gender | Male |
| NPI Issued | 06/18/2018 |
Brand vs generic prescribing mix · Typical
William Fox Jr - brand share 10.0%
Addiction Medicine (Preventive Medicine) Physician average
10% brand-name claims vs 90% generic, on 206 2024 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 2024.
206
Total Claims
$13K
Total Drug Cost
24
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 237.2
- Total Day Supply
- 6,596
- Brand vs Generic
- 10% brand / 90% generic
- Brand Drug Cost
- $6K
- Generic Drug Cost
- $8K
Patient Demographics
- Average Patient Age
- 52.9 years
- Avg HCC Risk Score
- 2.53
- Gender Split
- 46% female / 54% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What William Fox Jr prescribes most
Top Medicare Part D drugs by claim count, 2024
- Buprenorphine-Nalo…
Buprenorphine-Naloxone
17 claims
- Atorvastatin Calcium
Atorvastatin Calcium
16 claims
- Levothyroxine Sodium
Levothyroxine Sodium
15 claims
- Lisinopril
Lisinopril
15 claims
- Omeprazole
Omeprazole
11 claims
| Drug | Claims |
|---|---|
| Buprenorphine-Naloxone Buprenorphine Hcl/Naloxone Hcl | 17 |
| Atorvastatin Calcium | 16 |
| Levothyroxine Sodium | 15 |
| Lisinopril | 15 |
| Omeprazole | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Addiction Medicine (Preventive Medicine) Physician in AZ →
All providers in Arizona →
Compare specialties →
Addiction Medicine (Preventive Medicine) Physician Overview
How William Fox Jr fits within the Addiction Medicine (Preventive Medicine) Physician landscape nationally.
343
Addiction Medicine (Preventive Medicine) Physician Providers in US
46
States with Addiction Medicine (Preventive Medicine) Physician
929
Avg Claims per Provider
William Fox Jr's 206 claims are below the specialty average of 929.
Nationwide Addiction Medicine (Preventive Medicine) Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Fox Jr, both outside Arizona so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2018)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Addiction Medicine (Preventive Medicine) Physician Providers in Arizona
Other clinicians with the same primary specialty enrolled in Arizona, drawn from the same CMS NPPES roster as Fox Jr.
One of 9 Addiction Medicine (Preventive Medicine) Physician providers enrolled in Arizona, 5 are shown here.
Frequently Asked Questions
What is William Fox Jr's specialty? ▼
William Fox Jr specializes in Addiction Medicine (Preventive Medicine) Physician and practices in Litchfield Park, Arizona.
How much does William Fox Jr prescribe under Medicare Part D? ▼
In 2024, William Fox Jr wrote 206 Medicare Part D claims totaling $13K in drug costs for 24 beneficiaries.
Where is William Fox Jr located? ▼
William Fox Jr is located at 19590 W SAN MIGUEL AVE, Litchfield Park, AZ, 85340. Phone: (623) 377-0825.
What is William Fox Jr's NPI number? ▼
William Fox Jr's National Provider Identifier (NPI) is 1427542927, issued on 06/18/2018.
Does William Fox Jr prescribe more brand-name or generic drugs? ▼
William Fox Jr's prescribing is 10% brand-name and 90% generic drugs by claim count, with $6K in brand drug costs.
How many Addiction Medicine (Preventive Medicine) Physician providers are there in the US? ▼
There are 343 Addiction Medicine (Preventive Medicine) Physician providers across 46 states in the US. The average Addiction Medicine (Preventive Medicine) Physician provider writes 929 Medicare Part D claims per year.
What drugs does William Fox Jr prescribe most often? ▼
Based on 2024 Medicare Part D data, William Fox Jr's most frequently prescribed drugs include Buprenorphine-Naloxone, Atorvastatin Calcium, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Fox Jr accept Medicare? ▼
William Fox Jr appears in CMS Medicare data with 206 Part D claims and 24 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Fox Jr's credentials? ▼
William Fox Jr's NPI is 1427542927. 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 (2024). 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 August 2026 (NPPES) / 2024 (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
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 August 2026.