2026 NPPES data Nephrology Physician NPI 1952765034
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ALLEN CHAO

Nephrology 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
678
Medicare Part D claims · 152 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
79%
generic claims · 21% 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]
Industry payments
$22.91
1 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: ALLEN CHAO is a Nephrology Physician ([object Object]) practicing in SAN FRANCISCO, California with a Medicare Part D prescribing footprint of 678 claims across 152 beneficiaries — 21% brand-name prescribing . Their CMS MIPS Final Score of 74.4657/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $22.91 across 1 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: ALLEN CHAO reported a CMS MIPS final score of 74.4657 out of 100, below the 83.1 national average, and filed 678 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)

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

ALLEN CHAO at a glance

Below national average

NPI registry status

Active

Issued 04/05/2016

NPI 1952765034

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

678 53% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

MIPS final score

74.4657/100 8.634299999999996% pts

Mid-tier band

vs 83.1 national avg

Specialty distribution in California

How Nephrology Physician compares to other specialties among California providers

California providers

Nephrology Physician share within California

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

Medicare quality performance — MIPS

ALLEN CHAO's 2023 MIPS final score plotted against the Nephrology Physician national average

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

MIPS final score (Nephrology Physician) — 74.4657/100 vs national avg 83.1

0%100%National avg83%74.5%
MIPS final score (Nephrology 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).

ALLEN CHAO is a Nephrology Physician provider practicing in SAN FRANCISCO, California, according to the CMS National Plan and Provider Enumeration System (NPPES). NPI: 1952765034. 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.

ALLEN CHAO appears in the CMS NPPES registry as a Nephrology Physician provider at 400 PARNASSUS AVE, SAN FRANCISCO, CA, 94143, with a listed phone of (415) 353-2507. NPI 1952765034 was issued on 04/05/2016. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHAO 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 678 prescription claims written by this provider, covering 152 Medicare beneficiaries and totaling roughly $264K in drug spend, split 21% brand-name and 79% 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.

Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 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
SAN FRANCISCO, CA 94143

Provider Details

NPI 1952765034
Specialty Nephrology Physician
Gender Male
NPI Issued 04/05/2016

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

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 ALLEN CHAO. Source: openpaymentsdata.cms.gov.

Total received

$23

Largest payer

Otsuka America Pharmaceutical, 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 ALLEN CHAO. To verify ALLEN CHAO'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 · Typical

ALLEN CHAO — brand share 21.0%
Specialty average (est.)

21% brand-name claims vs 79% generic, on 678 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.

678
Total Claims
$264K
Total Drug Cost
152
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,694
Total Day Supply
50,312
Brand vs Generic
21% brand / 79% generic
Brand Drug Cost
$209K
Generic Drug Cost
$55K

Patient Demographics

Average Patient Age
74.1 years
Avg HCC Risk Score
2.89
Gender Split
46% female / 54% male
Age Distribution
<65: 15, 65-74: 60, 75-84: 57, 85+: 20

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Jardiance
Empagliflozin
68
Amlodipine Besylate
54
Irbesartan
46
Carvedilol
44
Amlodipine-Olmesartan
Amlodipine Bes/Olmesartan Med
38
Torsemide
38
Olmesartan Medoxomil
34
Chlorthalidone
29
Spironolactone
28
Furosemide
26

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

Nephrology Physician Overview

How ALLEN CHAO fits within the Nephrology Physician landscape nationally.

10,534
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider

ALLEN CHAO's 678 claims are below the specialty average of 1,454.

Nearby Nephrology Physician Providers in California

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

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

Frequently Asked Questions

What is ALLEN CHAO's specialty?
ALLEN CHAO specializes in Nephrology Physician and practices in SAN FRANCISCO, California.
How much does ALLEN CHAO prescribe under Medicare Part D?
In 2023, ALLEN CHAO wrote 678 Medicare Part D claims totaling $264K in drug costs for 152 beneficiaries.
What is ALLEN CHAO's Medicare quality score?
ALLEN CHAO 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 ALLEN CHAO located?
ALLEN CHAO is located at 400 PARNASSUS AVE, SAN FRANCISCO, CA, 94143. Phone: (415) 353-2507.
What is ALLEN CHAO's NPI number?
ALLEN CHAO's National Provider Identifier (NPI) is 1952765034, issued on 04/05/2016.
Does ALLEN CHAO prescribe more brand-name or generic drugs?
ALLEN CHAO's prescribing is 21% brand-name and 79% generic drugs by claim count, with $209K in brand drug costs.
How many Nephrology Physician providers are there in the US?
There are 10,534 Nephrology Physician providers across 55 states in the US. The average Nephrology Physician provider writes 1,454 Medicare Part D claims per year.
What drugs does ALLEN CHAO prescribe most often?
Based on 2023 Medicare Part D data, ALLEN CHAO's most frequently prescribed drugs include Jardiance, Amlodipine Besylate, Irbesartan. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does ALLEN CHAO accept Medicare?
ALLEN CHAO appears in CMS Medicare data with 678 Part D claims and 152 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify ALLEN CHAO's credentials?
ALLEN CHAO's NPI is 1952765034. 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