2026 NPPES data Nurse Practitioner NPI 1821505587 NP
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Janet William, NP

Nurse Practitioner in Cerritos, California. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers — including 87,227 in Nurse Practitioner, 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
452
Medicare Part D claims · 97 beneficiaries · Nurse Practitioner avg: 1K
Generic prescribing
88%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$5.5K
221 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Janet William, NP filed 452 Medicare Part D claims in 2023 as a Nurse Practitioner in Cerritos, California, prescribing 88% generic.

452
Part D claims, 2023
88%
generic prescribing
$5.5K
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.

Janet William, NP's Medicare Part D volume vs every U.S. prescriber

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

452 Top 38% higher than 62% 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%). This entry sits in this band. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. 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 Janet William, NP?

Quality data not reported

NPI registry status

Active

Issued 01/03/2018

NPI 1821505587

Primary specialty

Nurse Practitioner

High-volume

87,227 US NPIs in this specialty

Medicare Part D claims

452 58% vs specialty avg

2023 prescription claims

Specialty avg: 1,084

Specialty distribution in California

How Nurse Practitioner compares to other specialties among California providers

California providers

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

Behavior Technician — 17.3%Behavior Technician17.3%Marriage & Family Therapist — 5.5%Marriage & Family Therapist5.5%Student in an Organized Health Care Education/Training Program — 5%Student in an Organized Health Care Education/Training Program5%Mental Health Counselor — 3.9%Mental Health Counselor3.9%Pharmacist — 3.5%Pharmacist3.5%Clinical Social Worker — 3.1%Clinical Social Worker3.1%Nurse Practitioner — 0.7%Nurse Practitioner0.7%
Largest specialties in California (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Nurse Practitioner (ABMS / AOA reference)

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

Est. board-certified rate (Nurse Practitioner) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Nurse Practitioner) — 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).

Janet William, NP appears in the CMS NPPES registry as a Nurse Practitioner provider holding NP credentials at 18000 STUDEBAKER RD STE 800, Cerritos, CA, 90703, with a listed phone of (562) 735-3226. NPI 1821505587 was issued on 01/03/2018. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what William 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 452 prescription claims written by this provider, covering 97 Medicare beneficiaries and totaling roughly $122K in drug spend, split 12% brand-name and 88% generic by claim count, with an opioid prescribing rate of 31.4%. 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.

Nurse Practitioner is a high-volume specialty nationwide, with 87,227 enrolled providers across 56 states and an average of 1,084 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

18000 STUDEBAKER RD STE 800
Cerritos, CA 90703

Provider Details

NPI 1821505587
Specialty Nurse Practitioner
Credentials NP
Gender Female
NPI Issued 01/03/2018

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 Janet William, NP. Source: openpaymentsdata.cms.gov.

Total received

$5.5K

Largest payer

Novartis Pharmaceuticals Corporation

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 — California MBC 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 ~150K California medical licensees in 2023 — they are NOT specific to Janet William, NP. To verify Janet William, NP's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC 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 California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

Janet William, NP — brand share 12.0%
Nurse Practitioner average

12% brand-name claims vs 88% generic, on 452 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.

452
Total Claims
$122K
Total Drug Cost
97
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
551
Total Day Supply
14,561
Brand vs Generic
12% brand / 88% generic
Brand Drug Cost
$109K
Generic Drug Cost
$13K
Opioid Claims
142 (31.4% rate)
Antibiotic Claims
20

Patient Demographics

Average Patient Age
68.6 years
Avg HCC Risk Score
2.74
Gender Split
72% female / 28% male

Top Prescribed Drugs (Medicare Part D)

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

What Janet William, NP 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
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
82
Anastrozole
32
Ondansetron Hcl
30
Oxycodone-Acetaminophen
Oxycodone Hcl/Acetaminophen
22
Eliquis
Apixaban
19
Fentanyl
17
Prochlorperazine Maleate
15
Famotidine
14
Prednisone
14
Lorazepam
12

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

Nurse Practitioner Overview

How Janet William, NP fits within the Nurse Practitioner landscape nationally.

87,227
Nurse Practitioner Providers in US
56
States with Nurse Practitioner
1,084
Avg Claims per Provider

Janet William, NP's 452 claims are below the specialty average of 1,084.

Nearby Nurse Practitioner Providers in California

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

Compare Nurse Practitioner 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 California medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Nurse Practitioner 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 Janet William, NP's specialty?
Janet William, NP specializes in Nurse Practitioner and practices in Cerritos, California. Credentials: NP.
How much does Janet William, NP prescribe under Medicare Part D?
In 2023, Janet William, NP wrote 452 Medicare Part D claims totaling $122K in drug costs for 97 beneficiaries.
Where is Janet William, NP located?
Janet William, NP is located at 18000 STUDEBAKER RD STE 800, Cerritos, CA, 90703. Phone: (562) 735-3226.
What is Janet William, NP's NPI number?
Janet William, NP's National Provider Identifier (NPI) is 1821505587, issued on 01/03/2018.
Does Janet William, NP prescribe more brand-name or generic drugs?
Janet William, NP's prescribing is 12% brand-name and 88% generic drugs by claim count, with $109K in brand drug costs.
Does Janet William, NP prescribe opioids?
Yes, Janet William, NP had 142 opioid claims in 2023 with an opioid prescribing rate of 31.4%.
How many Nurse Practitioner providers are there in the US?
There are 87,227 Nurse Practitioner providers across 56 states in the US. The average Nurse Practitioner provider writes 1,084 Medicare Part D claims per year.
What drugs does Janet William, NP prescribe most often?
Based on 2023 Medicare Part D data, Janet William, NP's most frequently prescribed drugs include Hydrocodone-Acetaminophen, Anastrozole, Ondansetron Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Janet William, NP accept Medicare?
Janet William, NP appears in CMS Medicare data with 452 Part D claims and 97 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Janet William, NP's credentials?
Janet William, NP's NPI is 1821505587 with credentials NP. 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.