2026 NPPES data Cornea and External Diseases Specialist Physician NPI 1326304809 M.D.
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LUCY ZHANG, M.D.

Cornea and External Diseases Specialist Physician in GREENBRAE, 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
772
Medicare Part D claims · 261 beneficiaries · Cornea and External Diseases Specialist Physician avg: 1K
Generic prescribing
55%
generic claims · 45% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
75/100
▼ 8 pts below national avg 83.1 · [object Object]
Industry payments
$568.44
26 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: LUCY ZHANG, M.D. is a Cornea and External Diseases Specialist Physician ([object Object]) practicing in GREENBRAE, California with a Medicare Part D prescribing footprint of 772 claims across 261 beneficiaries — 45% brand-name prescribing . Their CMS MIPS Final Score of 75/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $568.44 across 26 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: LUCY ZHANG, M.D. reported a CMS MIPS final score of 75 out of 100, below the 83.1 national average, and filed 772 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

LUCY ZHANG, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

LUCY ZHANG, M.D. at a glance

Below national average

NPI registry status

Active

Issued 04/09/2012

NPI 1326304809

Primary specialty

Cornea and External Diseases Specialist Physician

Rare

294 US NPIs in this specialty

Medicare Part D claims

772 37% vs specialty avg

2023 prescription claims

Specialty avg: 1,232

MIPS final score

75/100 8.099999999999994% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in California

How Cornea and External Diseases Specialist Physician compares to other specialties among California providers

California providers

Cornea and External Diseases Specialist Physician share within California

1. Cornea and External Diseases Specialist Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Cornea and External Diseases Specialist Physician share within California

Medicare quality performance — MIPS

LUCY ZHANG, M.D.'s 2023 MIPS final score plotted against the Cornea and External Diseases Specialist Physician national average

Below national average
MIPS Final Score
75/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Cornea and External Diseases Specialist Physician) — 75/100 vs national avg 83.1

0%100%National avg83%75%
MIPS final score (Cornea and External Diseases Specialist Physician) — 75/100 vs national avg 83.1

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).

LUCY ZHANG, M.D. is a Cornea and External Diseases Specialist Physician provider practicing in GREENBRAE, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1326304809. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

LUCY ZHANG, M.D. appears in the CMS NPPES registry as a Cornea and External Diseases Specialist Physician provider holding M.D. credentials at 900 S ELISEO DR STE 102, GREENBRAE, CA, 94904, with a listed phone of (415) 461-8200. NPI 1326304809 was issued on 04/09/2012. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ZHANG 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 772 prescription claims written by this provider, covering 261 Medicare beneficiaries and totaling roughly $134K in drug spend, split 45% brand-name and 55% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 75/100 for the 2023 performance year, compared with the national average of 83.1.

Cornea and External Diseases Specialist Physician is a narrow specialty nationwide, with 294 enrolled providers across 43 states and an average of 1,232 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

900 S ELISEO DR STE 102
GREENBRAE, CA 94904

Provider Details

NPI 1326304809
Specialty Cornea and External Diseases Specialist Physician
Credentials M.D.
Gender Female
NPI Issued 04/09/2012

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

75
Final Score
Avg: 83.1

Reporting: Group practice

Hospital and facility affiliations

Facilities where LUCY ZHANG, 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.

ROBERT R ANDERSON MD INC
GREENBRAE, 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).

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 LUCY ZHANG, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$568

Largest payer

Bausch & Lomb Americas 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 — 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 LUCY ZHANG, M.D.. To verify LUCY ZHANG, M.D.'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 · Above average

LUCY ZHANG, M.D. — brand share 45.0%
Specialty average (est.)

45% brand-name claims vs 55% generic, on 772 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.

772
Total Claims
$134K
Total Drug Cost
261
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,689
Total Day Supply
48,988
Brand vs Generic
45% brand / 55% generic
Brand Drug Cost
$121K
Generic Drug Cost
$13K
Antibiotic Claims
24

Patient Demographics

Average Patient Age
79.9 years
Avg HCC Risk Score
1.07
Gender Split
62% female / 38% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Latanoprost
239
Timolol Maleate
105
Dorzolamide-Timolol
Dorzolamide Hcl/Timolol Maleat
80
Neomycin-Polymyxin-Dexameth
Neomycin/Polymyxin B/Dexametha
66
Prednisolone Acetate
44
Restasis
Cyclosporine
33
Brimonidine Tartrate
25
Dorzolamide Hcl
24
Xiidra
Lifitegrast
23
Doxycycline Monohydrate
20

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

Cornea and External Diseases Specialist Physician Overview

How LUCY ZHANG, M.D. fits within the Cornea and External Diseases Specialist Physician landscape nationally.

294
Cornea and External Diseases Specialist Physician Providers in US
43
States with Cornea and External Diseases Specialist Physician
1,232
Avg Claims per Provider

LUCY ZHANG, M.D.'s 772 claims are below the specialty average of 1,232.

Nearby Cornea and External Diseases Specialist Physician Providers in California

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

Compare Cornea and External Diseases Specialist Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is LUCY ZHANG, M.D.'s specialty?
LUCY ZHANG, M.D. specializes in Cornea and External Diseases Specialist Physician and practices in GREENBRAE, California. Credentials: M.D..
How much does LUCY ZHANG, M.D. prescribe under Medicare Part D?
In 2023, LUCY ZHANG, M.D. wrote 772 Medicare Part D claims totaling $134K in drug costs for 261 beneficiaries.
What is LUCY ZHANG, M.D.'s Medicare quality score?
LUCY ZHANG, M.D. has a CMS MIPS Final Score of 75/100. The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is LUCY ZHANG, M.D. located?
LUCY ZHANG, M.D. is located at 900 S ELISEO DR STE 102, GREENBRAE, CA, 94904. Phone: (415) 461-8200.
What is LUCY ZHANG, M.D.'s NPI number?
LUCY ZHANG, M.D.'s National Provider Identifier (NPI) is 1326304809, issued on 04/09/2012.
Does LUCY ZHANG, M.D. prescribe more brand-name or generic drugs?
LUCY ZHANG, M.D.'s prescribing is 45% brand-name and 55% generic drugs by claim count, with $121K in brand drug costs.
How many Cornea and External Diseases Specialist Physician providers are there in the US?
There are 294 Cornea and External Diseases Specialist Physician providers across 43 states in the US. The average Cornea and External Diseases Specialist Physician provider writes 1,232 Medicare Part D claims per year.
What drugs does LUCY ZHANG, M.D. prescribe most often?
Based on 2023 Medicare Part D data, LUCY ZHANG, M.D.'s most frequently prescribed drugs include Latanoprost, Timolol Maleate, Dorzolamide-Timolol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does LUCY ZHANG, M.D. accept Medicare?
LUCY ZHANG, M.D. appears in CMS Medicare data with 772 Part D claims and 261 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify LUCY ZHANG, M.D.'s credentials?
LUCY ZHANG, M.D.'s NPI is 1326304809 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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