2026 NPPES data Obstetrics & Gynecology Physician NPI 1366556102 MD
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Stephen Weinstein, MD

Obstetrics & Gynecology Physician in Walnut Creek, 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 44,313 in Obstetrics & Gynecology 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
142
Medicare Part D claims · 47 beneficiaries · Obstetrics & Gynecology Physician avg: 179
Generic prescribing
90%
generic claims · 10% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$17.44
1 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Stephen Weinstein, MD filed 142 Medicare Part D claims in 2023 as a Obstetrics & Gynecology Physician in Walnut Creek, California, prescribing 90% generic.

142
Part D claims, 2023
90%
generic prescribing
$17.44
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.

Stephen Weinstein, MD's Medicare Part D volume vs every U.S. prescriber

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

142 35th percentile higher than 35% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 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

Board-eligible specialty (heuristic — not verified)

Stephen Weinstein, 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 Stephen Weinstein, MD?

Quality data not reported

NPI registry status

Active

Issued 08/18/2006

NPI 1366556102

Primary specialty

Obstetrics & Gynecology Physician

Mid-sized

44,313 US NPIs in this specialty

Medicare Part D claims

142 21% vs specialty avg

2023 prescription claims

Specialty avg: 179

Specialty distribution in California

How Obstetrics & Gynecology Physician 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%Obstetrics & Gynecology Physician — 0.5%Obstetrics & Gynecology Physician0.5%
Largest specialties in California (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Obstetrics & Gynecology Physician (ABMS / AOA reference)

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

Est. board-certified rate (Obstetrics & Gynecology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Obstetrics & Gynecology 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).

Stephen Weinstein, MD appears in the CMS NPPES registry as a Obstetrics & Gynecology Physician provider holding MD credentials at 240 LA CASA VIA, Walnut Creek, CA, 94598, with a listed phone of (925) 932-2565. NPI 1366556102 was issued on 08/18/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Weinstein 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 142 prescription claims written by this provider, covering 47 Medicare beneficiaries and totaling roughly $14K in drug spend, split 10% brand-name and 90% generic by claim count. 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.

Obstetrics & Gynecology Physician is a mid-sized specialty nationwide, with 44,313 enrolled providers across 56 states and an average of 179 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

240 LA CASA VIA
Walnut Creek, CA 94598

Provider Details

NPI 1366556102
Specialty Obstetrics & Gynecology Physician
Credentials MD
Gender Male
NPI Issued 08/18/2006

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 Stephen Weinstein, MD. Source: openpaymentsdata.cms.gov.

Total received

$17

Largest payer

PFIZER INC.

Most common payment type

Education

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 Stephen Weinstein, MD. To verify Stephen Weinstein, MD'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

Stephen Weinstein, MD — brand share 10.0%
Obstetrics & Gynecology Physician average

10% brand-name claims vs 90% generic, on 142 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.

142
Total Claims
$14K
Total Drug Cost
47
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
313
Total Day Supply
8,932
Brand vs Generic
10% brand / 90% generic
Brand Drug Cost
$6K
Generic Drug Cost
$8K

Patient Demographics

Average Patient Age
75.6 years
Avg HCC Risk Score
0.72

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Estradiol
36
Raloxifene Hcl
12

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

Obstetrics & Gynecology Physician Overview

How Stephen Weinstein, MD fits within the Obstetrics & Gynecology Physician landscape nationally.

44,313
Obstetrics & Gynecology Physician Providers in US
56
States with Obstetrics & Gynecology Physician
179
Avg Claims per Provider

Stephen Weinstein, MD's 142 claims are below the specialty average of 179.

Nearby Obstetrics & Gynecology Physician Providers in California

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

Compare Obstetrics & Gynecology 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 California medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Obstetrics & Gynecology 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 Stephen Weinstein, MD's specialty?
Stephen Weinstein, MD specializes in Obstetrics & Gynecology Physician and practices in Walnut Creek, California. Credentials: MD.
How much does Stephen Weinstein, MD prescribe under Medicare Part D?
In 2023, Stephen Weinstein, MD wrote 142 Medicare Part D claims totaling $14K in drug costs for 47 beneficiaries.
Where is Stephen Weinstein, MD located?
Stephen Weinstein, MD is located at 240 LA CASA VIA, Walnut Creek, CA, 94598. Phone: (925) 932-2565.
What is Stephen Weinstein, MD's NPI number?
Stephen Weinstein, MD's National Provider Identifier (NPI) is 1366556102, issued on 08/18/2006.
Does Stephen Weinstein, MD prescribe more brand-name or generic drugs?
Stephen Weinstein, MD's prescribing is 10% brand-name and 90% generic drugs by claim count, with $6K in brand drug costs.
How many Obstetrics & Gynecology Physician providers are there in the US?
There are 44,313 Obstetrics & Gynecology Physician providers across 56 states in the US. The average Obstetrics & Gynecology Physician provider writes 179 Medicare Part D claims per year.
What drugs does Stephen Weinstein, MD prescribe most often?
Based on 2023 Medicare Part D data, Stephen Weinstein, MD's most frequently prescribed drugs include Estradiol, Raloxifene Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Stephen Weinstein, MD accept Medicare?
Stephen Weinstein, MD appears in CMS Medicare data with 142 Part D claims and 47 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Stephen Weinstein, MD's credentials?
Stephen Weinstein, MD's NPI is 1366556102 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.