2026 NPPES data Psychiatry Physician NPI 1396774436 MD
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PEGGY KWUN, MD

Psychiatry Physician in SAN RAFAEL, California. 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
2K
Medicare Part D claims · 463 beneficiaries · Psychiatry Physician avg: 1K
Generic prescribing
94%
generic claims · 6% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

PEGGY KWUN, MD filed 1,761 Medicare Part D claims in 2023 as a Psychiatry Physician in SAN RAFAEL, California, prescribing 94% generic.

2K
Part D claims, 2023
94%
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.

PEGGY KWUN, MD's Medicare Part D volume vs every U.S. prescriber

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

1,761 Top 17% higher than 83% 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%). This entry sits in this band. 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 certification likely (heuristic — not verified)

PEGGY KWUN, 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 PEGGY KWUN, MD?

Quality data not reported

NPI registry status

Active

Issued 07/01/2006

NPI 1396774436

Primary specialty

Psychiatry Physician

High-volume

53,104 US NPIs in this specialty

Medicare Part D claims

1,761 70% vs specialty avg

2023 prescription claims

Specialty avg: 1,038

Specialty distribution in California

How Psychiatry Physician compares to other specialties among California providers

California providers

Psychiatry Physician share within California

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

Specialty board-certification context

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

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

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

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

PEGGY KWUN, MD appears in the CMS NPPES registry as a Psychiatry Physician provider holding MD credentials at 111 SMITH RANCH RD, SAN RAFAEL, CA, 94903, with a listed phone of (415) 491-3000. NPI 1396774436 was issued on 07/01/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what KWUN 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 1,761 prescription claims written by this provider, covering 463 Medicare beneficiaries and totaling roughly $63K in drug spend, split 6% brand-name and 94% 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.

Psychiatry Physician is a high-volume specialty nationwide, with 53,104 enrolled providers across 56 states and an average of 1,038 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

111 SMITH RANCH RD
SAN RAFAEL, CA 94903

Provider Details

NPI 1396774436
Specialty Psychiatry Physician
Credentials MD
Gender Female
NPI Issued 07/01/2006

Hospital and facility affiliations

Facilities where PEGGY KWUN, 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.

PERMANENTE MEDICAL GROUP INC
SAN RAFAEL, CA

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

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 PEGGY KWUN, MD. To verify PEGGY KWUN, 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 · Generic-heavy

PEGGY KWUN, MD — brand share 6.0%
Specialty average (est.)

6% brand-name claims vs 94% generic, on 1,761 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.

1,761
Total Claims
$63K
Total Drug Cost
463
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
3,590
Total Day Supply
105,393
Brand vs Generic
6% brand / 94% generic
Brand Drug Cost
$27K
Generic Drug Cost
$36K

Patient Demographics

Average Patient Age
70.6 years
Avg HCC Risk Score
1.18
Gender Split
70% female / 30% male
Age Distribution
<65: 70, 65-74: 226, 75-84: 140, 85+: 27

Top Prescribed Drugs (Medicare Part D)

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

What PEGGY KWUN, 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
Lorazepam
156
Trazodone Hcl
101
Escitalopram Oxalate
96
Sertraline Hcl
86
Gabapentin
81
Duloxetine Hcl
74
Aripiprazole
72
Bupropion Xl
Bupropion Hcl
71
Clonazepam
66
Venlafaxine Hcl Er
Venlafaxine Hcl
64

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

Psychiatry Physician Overview

How PEGGY KWUN, MD fits within the Psychiatry Physician landscape nationally.

53,104
Psychiatry Physician Providers in US
56
States with Psychiatry Physician
1,038
Avg Claims per Provider

PEGGY KWUN, MD's 1,761 claims are above the specialty average of 1,038.

Nearby Psychiatry Physician Providers in California

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

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

Frequently Asked Questions

What is PEGGY KWUN, MD's specialty?
PEGGY KWUN, MD specializes in Psychiatry Physician and practices in SAN RAFAEL, California. Credentials: MD.
How much does PEGGY KWUN, MD prescribe under Medicare Part D?
In 2023, PEGGY KWUN, MD wrote 1,761 Medicare Part D claims totaling $63K in drug costs for 463 beneficiaries.
Where is PEGGY KWUN, MD located?
PEGGY KWUN, MD is located at 111 SMITH RANCH RD, SAN RAFAEL, CA, 94903. Phone: (415) 491-3000.
What is PEGGY KWUN, MD's NPI number?
PEGGY KWUN, MD's National Provider Identifier (NPI) is 1396774436, issued on 07/01/2006.
Does PEGGY KWUN, MD prescribe more brand-name or generic drugs?
PEGGY KWUN, MD's prescribing is 6% brand-name and 94% generic drugs by claim count, with $27K in brand drug costs.
How many Psychiatry Physician providers are there in the US?
There are 53,104 Psychiatry Physician providers across 56 states in the US. The average Psychiatry Physician provider writes 1,038 Medicare Part D claims per year.
What drugs does PEGGY KWUN, MD prescribe most often?
Based on 2023 Medicare Part D data, PEGGY KWUN, MD's most frequently prescribed drugs include Lorazepam, Trazodone Hcl, Escitalopram Oxalate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does PEGGY KWUN, MD accept Medicare?
PEGGY KWUN, MD appears in CMS Medicare data with 1,761 Part D claims and 463 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify PEGGY KWUN, MD's credentials?
PEGGY KWUN, MD's NPI is 1396774436 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