2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1043277601 MD
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WEI FENG, MD

Endocrinology, Diabetes & Metabolism Physician in SOUTH PASADENA, 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
6K
Medicare Part D claims · 497 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
53%
generic claims · 47% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
99.1275/100
▲ 16 pts above national avg 83.1 · [object Object]
Industry payments
$1.3K
50 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WEI FENG, MD reported a CMS MIPS final score of 99.1275/100 — above the 83.1 national average — and filed 6,118 Medicare Part D claims in 2023.

99.1275/100
MIPS score · +16 vs avg
6K
Part D claims, 2023
53%
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.

WEI FENG, MD's MIPS score vs every scored U.S. clinician

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

99 Top 9% higher than 91% 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%). Below this entry. 80–90: 129,887 scored providers (27%). Below this entry. 90–100: 189,403 scored providers (40%). This entry sits in this band. 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)

WEI FENG, MD 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).

What does the federal data show about WEI FENG, MD?

High performer (top quartile)

NPI registry status

Active

Issued 04/27/2006

NPI 1043277601

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

6,118 132% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

MIPS final score

99.1275/100 16.027500000000003% pts

Exceptional 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

WEI FENG, MD's 2023 MIPS final score plotted against the Endocrinology, Diabetes & Metabolism Physician national average

High performer (top quartile)
MIPS Final Score
99.1275/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Endocrinology, Diabetes & Metabolism Physician) — 99.1275/100 vs national avg 83.1

0%100%National avg83%99%
MIPS final score (Endocrinology, Diabetes & Metabolism Physician) — 99.1275/100 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).

WEI FENG, MD appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding MD credentials at 209 FAIR OAKS AVE, SOUTH PASADENA, CA, 91030, with a listed phone of (626) 396-2900. NPI 1043277601 was issued on 04/27/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FENG 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 6,118 prescription claims written by this provider, covering 497 Medicare beneficiaries and totaling roughly $2.5 million in drug spend, split 47% brand-name and 53% generic by claim count, with an opioid prescribing rate of 0.2%. 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 99.1275/100 for the 2023 performance year (Quality 85.2396), 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

209 FAIR OAKS AVE
SOUTH PASADENA, CA 91030

Provider Details

NPI 1043277601
Specialty Endocrinology, Diabetes & Metabolism Physician
Credentials MD
Gender Female
NPI Issued 04/27/2006

CMS Quality Score (MIPS)

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

99.1275
Final Score
Avg: 83.1
85.2396
Quality
100
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where WEI FENG, 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.

CITY OF HOPE MEDICAL FOUNDATION
DUARTE, 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 WEI FENG, MD. Source: openpaymentsdata.cms.gov.

Total received

$1.3K

Largest payer

Abbott Laboratories

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 WEI FENG, MD. To verify WEI FENG, 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 · Above average

WEI FENG, MD — brand share 47.0%
Specialty average (est.)

47% brand-name claims vs 53% generic, on 6,118 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.

6,118
Total Claims
$2.5M
Total Drug Cost
497
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
10,546
Total Day Supply
310,591
Brand vs Generic
47% brand / 53% generic
Brand Drug Cost
$2.3M
Generic Drug Cost
$124K
Opioid Claims
13 (0.2% rate)

Patient Demographics

Average Patient Age
74.2 years
Avg HCC Risk Score
1.68
Gender Split
66% female / 34% male
Age Distribution
<65: 43, 65-74: 213, 75-84: 178, 85+: 63

Top Prescribed Drugs (Medicare Part D)

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

What WEI FENG, 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
Levothyroxine Sodium
477
Jardiance
Empagliflozin
326
Synthroid
Levothyroxine Sodium
315
Farxiga
Dapagliflozin Propanediol
264
Metformin Hcl
258
Ozempic
Semaglutide
225
Atorvastatin Calcium
214
Alendronate Sodium
193
Metformin Hcl Er
Metformin Hcl
180
Tradjenta
Linagliptin
132

* 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 WEI FENG, MD 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

WEI FENG, MD's 6,118 claims are above 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 FENG.

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

Frequently Asked Questions

What is WEI FENG, MD's specialty?
WEI FENG, MD specializes in Endocrinology, Diabetes & Metabolism Physician and practices in SOUTH PASADENA, California. Credentials: MD.
How much does WEI FENG, MD prescribe under Medicare Part D?
In 2023, WEI FENG, MD wrote 6,118 Medicare Part D claims totaling $2.5M in drug costs for 497 beneficiaries.
What is WEI FENG, MD's Medicare quality score?
WEI FENG, MD has a CMS MIPS Final Score of 99.1275/100 (Quality: 85.2396). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is WEI FENG, MD located?
WEI FENG, MD is located at 209 FAIR OAKS AVE, SOUTH PASADENA, CA, 91030. Phone: (626) 396-2900.
What is WEI FENG, MD's NPI number?
WEI FENG, MD's National Provider Identifier (NPI) is 1043277601, issued on 04/27/2006.
Does WEI FENG, MD prescribe more brand-name or generic drugs?
WEI FENG, MD's prescribing is 47% brand-name and 53% generic drugs by claim count, with $2.3M in brand drug costs.
Does WEI FENG, MD prescribe opioids?
Yes, WEI FENG, MD had 13 opioid claims in 2023 with an opioid prescribing rate of 0.2%.
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 WEI FENG, MD prescribe most often?
Based on 2023 Medicare Part D data, WEI FENG, MD's most frequently prescribed drugs include Levothyroxine Sodium, Jardiance, Synthroid. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WEI FENG, MD accept Medicare?
WEI FENG, MD appears in CMS Medicare data with 6,118 Part D claims and 497 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WEI FENG, MD's credentials?
WEI FENG, MD's NPI is 1043277601 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.
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