2026 NPPES data Neurology Physician NPI 1821204314 M.D.
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Yih-Lin Nien, M.D.

Neurology Physician in Torrance, California. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers — including 19,866 in Neurology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration — see our methodology.

Federal data — no proprietary rating. We show these CMS records as-is — no composite score, no star rating, no editorial opinion layered on top.
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Yih-Lin Nien, M.D. is a Neurology Physician in Torrance, California, listed in the federal CMS National Provider Identifier registry.

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.

Board certification likely (heuristic — not verified)

Yih-Lin Nien, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 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 Yih-Lin Nien, M.D.?

Quality data not reported

NPI registry status

Active

Issued 05/14/2007

NPI 1821204314

Primary specialty

Neurology Physician

Mid-sized

19,866 US NPIs in this specialty

Specialty distribution in California

How Neurology Physician compares to other specialties among California providers

California providers

Largest specialties in California (% of in-state providers)

Behavior Technician — 17.3%Behavior Technician17.3%Marriage & Family Therapist — 5.5%Marriage & Family Therapist5.5%Student in an Organized Health Care Education/Training Program — 5%Student in an Organized Health Care Education/Training Program5%Mental Health Counselor — 3.9%Mental Health Counselor3.9%Pharmacist — 3.5%Pharmacist3.5%Clinical Social Worker — 3.1%Clinical Social Worker3.1%Neurology Physician — 0.2%Neurology Physician0.2%
Largest specialties in California (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Neurology Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Neurology Physician ABMS/AOA estimate

Est. board-certified rate (Neurology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Neurology 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).

Yih-Lin Nien, M.D. appears in the CMS NPPES registry as a Neurology Physician provider holding M.D. credentials at 4101 TORRANCE BLVD, Torrance, CA, 90503, with a listed phone of (310) 303-5250. NPI 1821204314 was issued on 05/14/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Nien 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 prescribing data is not currently published for this NPI, which typically means the provider either wrote fewer than 11 Part D claims in the most recent reporting year, does not participate in Medicare, or practices in a specialty that rarely prescribes outpatient drugs. Absence of prescribing data is not a quality signal — many Neurology Physician providers operate outside Part D entirely.

Neurology Physician is a mid-sized specialty nationwide, with 19,866 enrolled providers across 54 states and an average of 1,309 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

4101 TORRANCE BLVD
Torrance, CA 90503

Provider Details

NPI 1821204314
Specialty Neurology Physician
Credentials M.D.
Gender Male
NPI Issued 05/14/2007

Hospital and facility affiliations

Facilities where Yih-Lin Nien, 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.

Providence Medical Institute
Torrance, 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 Yih-Lin Nien, M.D.. To verify Yih-Lin Nien, 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.

Neurology Physician Overview

How Yih-Lin Nien, M.D. fits within the Neurology Physician landscape nationally.

19,866
Neurology Physician Providers in US
54
States with Neurology Physician
1,309
Avg Claims per Provider

Nearby Neurology Physician Providers in California

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

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

Before you book an appointment

Use this federal record as your verification checklist, not as a recommendation.

  • Confirm the NPI record is current in the official CMS registry — providers update their own NPPES details, and moves can lag. Verify this NPI
  • Check the active license and any disciplinary history with the California medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Neurology Physician peer on Medicare volume and prescribing patterns. Compare providers

Medicare Part D and MIPS figures describe practice patterns in federal programs only — they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.

Frequently Asked Questions

What is Yih-Lin Nien, M.D.'s specialty?
Yih-Lin Nien, M.D. specializes in Neurology Physician and practices in Torrance, California. Credentials: M.D..
Where is Yih-Lin Nien, M.D. located?
Yih-Lin Nien, M.D. is located at 4101 TORRANCE BLVD, Torrance, CA, 90503. Phone: (310) 303-5250.
What is Yih-Lin Nien, M.D.'s NPI number?
Yih-Lin Nien, M.D.'s National Provider Identifier (NPI) is 1821204314, issued on 05/14/2007.
How many Neurology Physician providers are there in the US?
There are 19,866 Neurology Physician providers across 54 states in the US. The average Neurology Physician provider writes 1,309 Medicare Part D claims per year.
Does Yih-Lin Nien, M.D. accept Medicare?
Yih-Lin Nien, M.D. appears in CMS Medicare data. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Yih-Lin Nien, M.D.'s credentials?
Yih-Lin Nien, M.D.'s NPI is 1821204314 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.
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

Compiled from official public sources by the PlainDoctor editorial team.