2026 NPPES data Specialist NPI 1316902919 M.D.
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WILLIAM GROS, M.D.

Specialist in LA GRANGE, Illinois. 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
8K
Medicare Part D claims · 550 beneficiaries · Specialist avg: 1K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$292.63
12 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WILLIAM GROS, M.D. filed 7,558 Medicare Part D claims in 2023 as a Specialist in LA GRANGE, Illinois, prescribing 89% generic.

8K
Part D claims, 2023
89%
generic prescribing
$292.63
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 GROS, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

7,558 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 WILLIAM GROS, M.D.?

Quality data not reported

NPI registry status

Active

Issued 04/18/2006

NPI 1316902919

Primary specialty

Specialist

High-volume

69,658 US NPIs in this specialty

Medicare Part D claims

7,558 413% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

Specialty distribution in Illinois

How Specialist compares to other specialties among Illinois providers

Illinois providers

Specialist share within Illinois

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

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).

WILLIAM GROS, M.D. appears in the CMS NPPES registry as a Specialist provider holding M.D. credentials at 512 W BURLINGTON AVE, LA GRANGE, IL, 60525, with a listed phone of (630) 579-4801. NPI 1316902919 was issued on 04/18/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GROS 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 7,558 prescription claims written by this provider, covering 550 Medicare beneficiaries and totaling roughly $803K in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 1.8%. 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

512 W BURLINGTON AVE
LA GRANGE, IL 60525

Provider Details

NPI 1316902919
Specialty Specialist
Credentials M.D.
Gender Male
NPI Issued 04/18/2006

Hospital and facility affiliations

Facilities where WILLIAM GROS, M.D. 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.

DUPAGE MEDICAL GROUP LTD
LAGRANGE, IL

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 GROS, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$293

Largest payer

Novo Nordisk 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.

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 GROS, M.D.. To verify WILLIAM GROS, M.D.'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 GROS, M.D. — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 7,558 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.

7,558
Total Claims
$803K
Total Drug Cost
550
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
18,000
Total Day Supply
514,450
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$649K
Generic Drug Cost
$149K
Opioid Claims
134 (1.8% rate)
Antibiotic Claims
405

Patient Demographics

Average Patient Age
76.2 years
Avg HCC Risk Score
1.28
Gender Split
49% female / 51% male
Age Distribution
<65: 14, 65-74: 239, 75-84: 190, 85+: 107

Top Prescribed Drugs (Medicare Part D)

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

What WILLIAM GROS, M.D. 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
427
Levothyroxine Sodium
373
Lisinopril
331
Amlodipine Besylate
324
Metformin Hcl Er
Metformin Hcl
292
Simvastatin
235
Hydrochlorothiazide
215
Metoprolol Succinate
168
Pantoprazole Sodium
168
Triamterene-Hydrochlorothiazid
Triamterene/Hydrochlorothiazid
155

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

Specialist Overview

How WILLIAM GROS, M.D. fits within the Specialist landscape nationally.

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

WILLIAM GROS, M.D.'s 7,558 claims are above the specialty average of 1,474.

Nearby Specialist Providers in Illinois

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

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

Frequently Asked Questions

What is WILLIAM GROS, M.D.'s specialty?
WILLIAM GROS, M.D. specializes in Specialist and practices in LA GRANGE, Illinois. Credentials: M.D..
How much does WILLIAM GROS, M.D. prescribe under Medicare Part D?
In 2023, WILLIAM GROS, M.D. wrote 7,558 Medicare Part D claims totaling $803K in drug costs for 550 beneficiaries.
Where is WILLIAM GROS, M.D. located?
WILLIAM GROS, M.D. is located at 512 W BURLINGTON AVE, LA GRANGE, IL, 60525. Phone: (630) 579-4801.
What is WILLIAM GROS, M.D.'s NPI number?
WILLIAM GROS, M.D.'s National Provider Identifier (NPI) is 1316902919, issued on 04/18/2006.
Does WILLIAM GROS, M.D. prescribe more brand-name or generic drugs?
WILLIAM GROS, M.D.'s prescribing is 11% brand-name and 89% generic drugs by claim count, with $649K in brand drug costs.
Does WILLIAM GROS, M.D. prescribe opioids?
Yes, WILLIAM GROS, M.D. had 134 opioid claims in 2023 with an opioid prescribing rate of 1.8%.
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 WILLIAM GROS, M.D. prescribe most often?
Based on 2023 Medicare Part D data, WILLIAM GROS, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Levothyroxine Sodium, Lisinopril. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WILLIAM GROS, M.D. accept Medicare?
WILLIAM GROS, M.D. appears in CMS Medicare data with 7,558 Part D claims and 550 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WILLIAM GROS, M.D.'s credentials?
WILLIAM GROS, M.D.'s NPI is 1316902919 with credentials M.D.. 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