2026 NPPES data Family Medicine Physician NPI 1144212382 MD
Verify on CMS →

William Martinez, MD

Family Medicine Physician in Libertyville, Illinois. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 147,640 in Family 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
2K
Medicare Part D claims · 142 beneficiaries · Family Medicine Physician avg: 3K
Generic prescribing
85%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.3K
41 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

William Martinez, MD filed 2,092 Medicare Part D claims in 2023 as a Family Medicine Physician in Libertyville, Illinois, prescribing 85% generic.

2K
Part D claims, 2023
85%
generic prescribing
$1.3K
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.

William Martinez, MD's Medicare Part D volume vs every U.S. prescriber

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

2,092 Top 16% higher than 84% 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. 2K+: 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)

William Martinez, 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 William Martinez, MD?

Quality data not reported

NPI registry status

Active

Issued 08/15/2005

NPI 1144212382

Primary specialty

Family Medicine Physician

High-volume

147,640 US NPIs in this specialty

Medicare Part D claims

2,092 39% vs specialty avg

2023 prescription claims

Specialty avg: 3,418

Specialty distribution in Illinois

How Family Medicine Physician compares to other specialties among Illinois providers

Illinois providers

Largest specialties in Illinois (% of in-state providers)

Clinical Social Worker - 5.2%Clinical Social Worker5.2%Physical Therapist - 5%Physical Therapist5%Mental Health Counselor - 4.5%Mental Health Counselor4.5%Speech-Language Pathologist - 4.2%Speech-Language Pathologist4.2%Student in an Organized Health Care Education/Training Program - 4.2%Student in an Organized Health Care Education/Training Program4.2%Pharmacist - 4.1%Pharmacist4.1%Family Medicine Physician - 2.5%Family Medicine Physician2.5%
Largest specialties in Illinois (% of in-state 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 Family Medicine Physician. Verify directly:

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 Martinez, MD appears in the CMS NPPES registry as a Family Medicine Physician provider holding MD credentials at 1870 W WINCHESTER RD, Libertyville, IL, 60048, with a listed phone of (847) 996-0700. NPI 1144212382 was issued on 08/15/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Martinez 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 2,092 prescription claims written by this provider, covering 142 Medicare beneficiaries and totaling roughly $233K in drug spend, split 13% brand-name and 85% generic by claim count, with an opioid prescribing rate of 0.9%. 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.

Family Medicine Physician is a high-volume specialty nationwide, with 147,640 enrolled providers across 56 states and an average of 3,418 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

1870 W WINCHESTER RD
Libertyville, IL 60048

Provider Details

NPI 1144212382
Specialty Family Medicine Physician
Credentials MD
Gender Male
NPI Issued 08/15/2005

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

Total received

$1.3K

Largest payer

AstraZeneca Pharmaceuticals LP

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 William Martinez, MD. To verify William Martinez, MD'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 · Typical

William Martinez, MD - brand share 13.0%
Family Medicine Physician average

13% brand-name claims vs 85% generic, on 2,092 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.

2,092
Total Claims
$233K
Total Drug Cost
142
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
4,935
Total Day Supply
144,765
Brand vs Generic
13% brand / 85% generic
Brand Drug Cost
$199K
Generic Drug Cost
$32K
Opioid Claims
19 (0.9% rate)
Antibiotic Claims
47

Patient Demographics

Average Patient Age
73.7 years
Avg HCC Risk Score
1.05
Gender Split
47% female / 53% male

Top Prescribed Drugs (Medicare Part D)

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

What William Martinez, 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
103
Losartan Potassium
71
Metformin Hcl
70
Metformin Hcl Er
Metformin Hcl
67
Pravastatin Sodium
62
Levothyroxine Sodium
61
Amlodipine Besylate
60
Lisinopril
59
Lorazepam
53
Carvedilol
52

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

Family Medicine Physician Overview

How William Martinez, MD fits within the Family Medicine Physician landscape nationally.

147,640
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider

William Martinez, MD's 2,092 claims are below the specialty average of 3,418.

Nearby Family Medicine Physician Providers in Illinois

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

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

Before you book an appointment

Use this federal record as your verification checklist, not as a recommendation.

  • Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
  • Check the active license and any disciplinary history with the Illinois medical board, federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Family Medicine Physician peer on Medicare volume and prescribing patterns. Compare providers

Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.

Frequently Asked Questions

What is William Martinez, MD's specialty?
William Martinez, MD specializes in Family Medicine Physician and practices in Libertyville, Illinois. Credentials: MD.
How much does William Martinez, MD prescribe under Medicare Part D?
In 2023, William Martinez, MD wrote 2,092 Medicare Part D claims totaling $233K in drug costs for 142 beneficiaries.
Where is William Martinez, MD located?
William Martinez, MD is located at 1870 W WINCHESTER RD, Libertyville, IL, 60048. Phone: (847) 996-0700.
What is William Martinez, MD's NPI number?
William Martinez, MD's National Provider Identifier (NPI) is 1144212382, issued on 08/15/2005.
Does William Martinez, MD prescribe more brand-name or generic drugs?
William Martinez, MD's prescribing is 13% brand-name and 85% generic drugs by claim count, with $199K in brand drug costs.
Does William Martinez, MD prescribe opioids?
Yes, William Martinez, MD had 19 opioid claims in 2023 with an opioid prescribing rate of 0.9%.
How many Family Medicine Physician providers are there in the US?
There are 147,640 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does William Martinez, MD prescribe most often?
Based on 2023 Medicare Part D data, William Martinez, MD's most frequently prescribed drugs include Atorvastatin Calcium, Losartan Potassium, Metformin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does William Martinez, MD accept Medicare?
William Martinez, MD appears in CMS Medicare data with 2,092 Part D claims and 142 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify William Martinez, MD's credentials?
William Martinez, MD's NPI is 1144212382 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

Compiled from official public sources by the PlainDoctor editorial team.