2026 NPPES data Pediatrics Physician NPI 1619909868 MD
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ROBERT WILLIAMS, MD

Pediatrics Physician in NEW BERLIN, Wisconsin. 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
4K
Medicare Part D claims · 304 beneficiaries · Pediatrics Physician avg: 762
Generic prescribing
86%
generic claims · 14% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

ROBERT WILLIAMS, MD filed 4,450 Medicare Part D claims in 2023 as a Pediatrics Physician in NEW BERLIN, Wisconsin, prescribing 86% generic.

4K
Part D claims, 2023
86%
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.

ROBERT WILLIAMS, MD's Medicare Part D volume vs every U.S. prescriber

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

4,450 Top 7% higher than 93% 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)

ROBERT WILLIAMS, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — 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 ROBERT WILLIAMS, MD?

Quality data not reported

NPI registry status

Active

Issued 07/07/2006

NPI 1619909868

Primary specialty

Pediatrics Physician

High-volume

80,574 US NPIs in this specialty

Medicare Part D claims

4,450 484% vs specialty avg

2023 prescription claims

Specialty avg: 762

Specialty distribution in Wisconsin

How Pediatrics Physician compares to other specialties among Wisconsin providers

Wisconsin providers

Pediatrics Physician share within Wisconsin

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Pediatrics 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).

ROBERT WILLIAMS, MD appears in the CMS NPPES registry as a Pediatrics Physician provider holding MD credentials at 14555 W NATIONAL AVE, NEW BERLIN, WI, 53151, with a listed phone of (262) 827-3636. NPI 1619909868 was issued on 07/07/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what WILLIAMS 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 4,450 prescription claims written by this provider, covering 304 Medicare beneficiaries and totaling roughly $466K in drug spend, split 14% brand-name and 86% generic by claim count, with an opioid prescribing rate of 0.8%. 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.

Pediatrics Physician is a high-volume specialty nationwide, with 80,574 enrolled providers across 56 states and an average of 762 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

14555 W NATIONAL AVE
NEW BERLIN, WI 53151

Provider Details

NPI 1619909868
Specialty Pediatrics Physician
Credentials MD
Gender Male
NPI Issued 07/07/2006

Hospital and facility affiliations

Facilities where ROBERT WILLIAMS, 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.

AURORA ADVANCED HEALTHCARE, INC.
WAUWATOSA, WI

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Brand vs generic prescribing mix · Typical

ROBERT WILLIAMS, MD — brand share 14.0%
Specialty average (est.)

14% brand-name claims vs 86% generic, on 4,450 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.

4,450
Total Claims
$466K
Total Drug Cost
304
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
10,128
Total Day Supply
295,796
Brand vs Generic
14% brand / 86% generic
Brand Drug Cost
$380K
Generic Drug Cost
$84K
Opioid Claims
34 (0.8% rate)
Antibiotic Claims
31

Patient Demographics

Average Patient Age
74.6 years
Avg HCC Risk Score
1.25
Gender Split
37% female / 63% male
Age Distribution
<65: 18, 65-74: 144, 75-84: 96, 85+: 46

Top Prescribed Drugs (Medicare Part D)

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

What ROBERT WILLIAMS, 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
Lisinopril
269
Atorvastatin Calcium
194
Pravastatin Sodium
175
Simvastatin
147
Levothyroxine Sodium
143
Hydrochlorothiazide
132
Tamsulosin Hcl
120
Amlodipine Besylate
109
Pantoprazole Sodium
104
Furosemide
102

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

Pediatrics Physician Overview

How ROBERT WILLIAMS, MD fits within the Pediatrics Physician landscape nationally.

80,574
Pediatrics Physician Providers in US
56
States with Pediatrics Physician
762
Avg Claims per Provider

ROBERT WILLIAMS, MD's 4,450 claims are above the specialty average of 762.

Nearby Pediatrics Physician Providers in Wisconsin

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

Compare Pediatrics Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is ROBERT WILLIAMS, MD's specialty?
ROBERT WILLIAMS, MD specializes in Pediatrics Physician and practices in NEW BERLIN, Wisconsin. Credentials: MD.
How much does ROBERT WILLIAMS, MD prescribe under Medicare Part D?
In 2023, ROBERT WILLIAMS, MD wrote 4,450 Medicare Part D claims totaling $466K in drug costs for 304 beneficiaries.
Where is ROBERT WILLIAMS, MD located?
ROBERT WILLIAMS, MD is located at 14555 W NATIONAL AVE, NEW BERLIN, WI, 53151. Phone: (262) 827-3636.
What is ROBERT WILLIAMS, MD's NPI number?
ROBERT WILLIAMS, MD's National Provider Identifier (NPI) is 1619909868, issued on 07/07/2006.
Does ROBERT WILLIAMS, MD prescribe more brand-name or generic drugs?
ROBERT WILLIAMS, MD's prescribing is 14% brand-name and 86% generic drugs by claim count, with $380K in brand drug costs.
Does ROBERT WILLIAMS, MD prescribe opioids?
Yes, ROBERT WILLIAMS, MD had 34 opioid claims in 2023 with an opioid prescribing rate of 0.8%.
How many Pediatrics Physician providers are there in the US?
There are 80,574 Pediatrics Physician providers across 56 states in the US. The average Pediatrics Physician provider writes 762 Medicare Part D claims per year.
What drugs does ROBERT WILLIAMS, MD prescribe most often?
Based on 2023 Medicare Part D data, ROBERT WILLIAMS, MD's most frequently prescribed drugs include Lisinopril, Atorvastatin Calcium, Pravastatin Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does ROBERT WILLIAMS, MD accept Medicare?
ROBERT WILLIAMS, MD appears in CMS Medicare data with 4,450 Part D claims and 304 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify ROBERT WILLIAMS, MD's credentials?
ROBERT WILLIAMS, MD's NPI is 1619909868 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