2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1659418655 MD, PHD
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VICTORIA HSIAO, MD, PHD

Endocrinology, Diabetes & Metabolism Physician in SAN FRANCISCO, 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 · 203 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
50%
generic claims · 50% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
74.4657/100
▼ 9 pts below national avg 83.1 · [object Object]

What the federal data shows

VICTORIA HSIAO, MD, PHD reported a CMS MIPS final score of 74.4657/100 — below the 83.1 national average — and filed 1,640 Medicare Part D claims in 2023.

74.4657/100
MIPS score · -9 vs avg
2K
Part D claims, 2023
50%
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.

VICTORIA HSIAO, MD, PHD's MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

74 12th percentile higher than 12% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). This entry sits in this band. 80–90: 129,887 scored providers (27%). Above this entry. 90–100: 189,403 scored providers (40%). Above this entry. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

Board certification likely (heuristic — not verified)

VICTORIA HSIAO, MD, PHD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 3 hospital affiliations — 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 VICTORIA HSIAO, MD, PHD?

Below national average

NPI registry status

Active

Issued 01/30/2007

NPI 1659418655

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

1,640 38% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

MIPS final score

74.4657/100 8.634299999999996% pts

Mid-tier band

vs 83.1 national avg

Specialty distribution in California

How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among California providers

California providers

Endocrinology, Diabetes & Metabolism Physician share within California

1. Endocrinology, Diabetes & Metabolism Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Endocrinology, Diabetes & Metabolism Physician share within California

Medicare quality performance — MIPS

VICTORIA HSIAO, MD, PHD's 2023 MIPS final score plotted against the Endocrinology, Diabetes & Metabolism Physician national average

Below national average
MIPS Final Score
74.4657/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Endocrinology, Diabetes & Metabolism Physician) — 74.4657/100 vs national avg 83.1

0%100%National avg83%74.5%
MIPS final score (Endocrinology, Diabetes & Metabolism Physician) — 74.4657/100 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).

VICTORIA HSIAO, MD, PHD appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding MD, PHD credentials at 400 PARNASSUS AVE STE A550, SAN FRANCISCO, CA, 94143, with a listed phone of (415) 353-2350. NPI 1659418655 was issued on 01/30/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HSIAO 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 1,640 prescription claims written by this provider, covering 203 Medicare beneficiaries and totaling roughly $985K in drug spend, split 50% brand-name and 50% 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 74.4657/100 for the 2023 performance year, compared with the national average of 83.1.

Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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

400 PARNASSUS AVE STE A550
SAN FRANCISCO, CA 94143

Provider Details

NPI 1659418655
Specialty Endocrinology, Diabetes & Metabolism Physician
Credentials MD, PHD
Gender Female
NPI Issued 01/30/2007

CMS Quality Score (MIPS)

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

74.4657
Final Score
Avg: 83.1
46.6814
Cost
76
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where VICTORIA HSIAO, MD, PHD 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.

REGENTS OF THE UNIVERSITY OF CALIFORNIA
SAN FRANCISCO, CA
UCSF MEDICAL GROUP BUSINESS SERVICES
SAN FRANCISCO, CA
UNIVERSITY OF CALIFORNIA SAN FRANCISCO
SAN FRANCISCO, 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 VICTORIA HSIAO, MD, PHD. To verify VICTORIA HSIAO, MD, PHD'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 · Brand-heavy

VICTORIA HSIAO, MD, PHD — brand share 50.0%
Specialty average (est.)

50% brand-name claims vs 50% generic, on 1,640 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.

1,640
Total Claims
$985K
Total Drug Cost
203
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
3,956
Total Day Supply
117,806
Brand vs Generic
50% brand / 50% generic
Brand Drug Cost
$924K
Generic Drug Cost
$26K

Patient Demographics

Average Patient Age
71.1 years
Avg HCC Risk Score
1.93
Gender Split
57% female / 43% male

Top Prescribed Drugs (Medicare Part D)

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

What VICTORIA HSIAO, MD, PHD 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
Ozempic
Semaglutide
146
Rosuvastatin Calcium
120
Levothyroxine Sodium
85
Metformin Hcl
83
Jardiance
Empagliflozin
79
Tresiba Flextouch U-100
Insulin Degludec
72
Atorvastatin Calcium
70
Metformin Hcl Er
Metformin Hcl
67
Novolog Flexpen
Insulin Aspart
56
Glipizide Er
Glipizide
48

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

Endocrinology, Diabetes & Metabolism Physician Overview

How VICTORIA HSIAO, MD, PHD fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.

7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider

VICTORIA HSIAO, MD, PHD's 1,640 claims are below the specialty average of 2,639.

Nearby Endocrinology, Diabetes & Metabolism Physician Providers in California

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

Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is VICTORIA HSIAO, MD, PHD's specialty?
VICTORIA HSIAO, MD, PHD specializes in Endocrinology, Diabetes & Metabolism Physician and practices in SAN FRANCISCO, California. Credentials: MD, PHD.
How much does VICTORIA HSIAO, MD, PHD prescribe under Medicare Part D?
In 2023, VICTORIA HSIAO, MD, PHD wrote 1,640 Medicare Part D claims totaling $985K in drug costs for 203 beneficiaries.
What is VICTORIA HSIAO, MD, PHD's Medicare quality score?
VICTORIA HSIAO, MD, PHD has a CMS MIPS Final Score of 74.4657/100, Cost: 46.6814. The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is VICTORIA HSIAO, MD, PHD located?
VICTORIA HSIAO, MD, PHD is located at 400 PARNASSUS AVE STE A550, SAN FRANCISCO, CA, 94143. Phone: (415) 353-2350.
What is VICTORIA HSIAO, MD, PHD's NPI number?
VICTORIA HSIAO, MD, PHD's National Provider Identifier (NPI) is 1659418655, issued on 01/30/2007.
Does VICTORIA HSIAO, MD, PHD prescribe more brand-name or generic drugs?
VICTORIA HSIAO, MD, PHD's prescribing is 50% brand-name and 50% generic drugs by claim count, with $924K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US?
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
What drugs does VICTORIA HSIAO, MD, PHD prescribe most often?
Based on 2023 Medicare Part D data, VICTORIA HSIAO, MD, PHD's most frequently prescribed drugs include Ozempic, Rosuvastatin Calcium, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does VICTORIA HSIAO, MD, PHD accept Medicare?
VICTORIA HSIAO, MD, PHD appears in CMS Medicare data with 1,640 Part D claims and 203 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify VICTORIA HSIAO, MD, PHD's credentials?
VICTORIA HSIAO, MD, PHD's NPI is 1659418655 with credentials MD, PHD. 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