2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1477842458
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JANET CHIANG

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
32
Medicare Part D claims · 12 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
53%
generic claims · 47% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

JANET CHIANG filed 32 Medicare Part D claims in 2023 as a Endocrinology, Diabetes & Metabolism Physician in SAN FRANCISCO, California, prescribing 53% generic.

32
Part D claims, 2023
53%
generic prescribing

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 CHIANG's Medicare Part D volume vs every U.S. prescriber

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

32 0th percentile higher than 0% 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)

JANET CHIANG 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 JANET CHIANG?

Quality data not reported

NPI registry status

Active

Issued 03/30/2011

NPI 1477842458

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

32 99% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

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

Specialty board-certification context

Estimated specialty board-certified rate — Endocrinology, Diabetes & Metabolism Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Endocrinology, Diabetes & Metabolism Physician ABMS/AOA estimate

Est. board-certified rate (Endocrinology, Diabetes & Metabolism Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Endocrinology, Diabetes & Metabolism 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).

JANET CHIANG appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider at 505 PARNASSUS AVE, SAN FRANCISCO, CA, 94143, with a listed phone of (415) 234-3960. NPI 1477842458 was issued on 03/30/2011. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHIANG 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 32 prescription claims written by this provider, covering 12 Medicare beneficiaries and totaling roughly $18K in drug spend, split 47% brand-name and 53% 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.

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

505 PARNASSUS AVE
SAN FRANCISCO, CA 94143

Provider Details

NPI 1477842458
Specialty Endocrinology, Diabetes & Metabolism Physician
Gender Female
NPI Issued 03/30/2011

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 CHIANG. To verify JANET CHIANG'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

JANET CHIANG — brand share 47.0%
Specialty average (est.)

47% brand-name claims vs 53% generic, on 32 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.

32
Total Claims
$18K
Total Drug Cost
12
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
76
Total Day Supply
2,266
Brand vs Generic
47% brand / 53% generic
Brand Drug Cost
$18K
Generic Drug Cost
$477

Patient Demographics

Average Patient Age
70.6 years
Avg HCC Risk Score
0.67
Age Distribution
<65: 0, 65-74: N/A, 75-84: N/A, 85+: 0

Endocrinology, Diabetes & Metabolism Physician Overview

How JANET CHIANG 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

JANET CHIANG's 32 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 CHIANG.

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

Frequently Asked Questions

What is JANET CHIANG's specialty?
JANET CHIANG specializes in Endocrinology, Diabetes & Metabolism Physician and practices in SAN FRANCISCO, California.
How much does JANET CHIANG prescribe under Medicare Part D?
In 2023, JANET CHIANG wrote 32 Medicare Part D claims totaling $18K in drug costs for 12 beneficiaries.
Where is JANET CHIANG located?
JANET CHIANG is located at 505 PARNASSUS AVE, SAN FRANCISCO, CA, 94143. Phone: (415) 234-3960.
What is JANET CHIANG's NPI number?
JANET CHIANG's National Provider Identifier (NPI) is 1477842458, issued on 03/30/2011.
Does JANET CHIANG prescribe more brand-name or generic drugs?
JANET CHIANG's prescribing is 47% brand-name and 53% generic drugs by claim count, with $18K 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.
Does JANET CHIANG accept Medicare?
JANET CHIANG appears in CMS Medicare data with 32 Part D claims and 12 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JANET CHIANG's credentials?
JANET CHIANG's NPI is 1477842458. 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