2026 NPPES data Hematology & Oncology Physician NPI 1003159427 M.D.
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Sarah Tomassetti, M.D.

Hematology & Oncology 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 11,215 in Hematology & Oncology 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.
Prescribing volume
16
Medicare Part D claims · Hematology & Oncology Physician avg: 847
Industry payments
$7.2K
8 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Sarah Tomassetti, M.D. filed 16 Medicare Part D claims in 2023 as a Hematology & Oncology Physician in Torrance, California.

16
Part D claims, 2023
$7.2K
industry payments (Sunshine Act)

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.

Sarah Tomassetti, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

16 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)

Sarah Tomassetti, M.D. 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 Sarah Tomassetti, M.D.?

Quality data not reported

NPI registry status

Active

Issued 04/03/2013

NPI 1003159427

Primary specialty

Hematology & Oncology Physician

Mid-sized

11,215 US NPIs in this specialty

Medicare Part D claims

16 98% vs specialty avg

2023 prescription claims

Specialty avg: 847

Specialty distribution in California

How Hematology & Oncology 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%Hematology & Oncology Physician — 0.1%Hematology & Oncology Physician0.1%
Largest specialties in California (% of in-state providers)

Specialty board-certification context

Estimated specialty board-certified rate — Hematology & Oncology Physician (ABMS / AOA reference)

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

Est. board-certified rate (Hematology & Oncology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Hematology & Oncology 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).

Sarah Tomassetti, M.D. appears in the CMS NPPES registry as a Hematology & Oncology Physician provider holding M.D. credentials at 1000 W CARSON ST # N18, Torrance, CA, 90502, with a listed phone of (310) 745-2882. NPI 1003159427 was issued on 04/03/2013. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Tomassetti 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 16 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $506 in drug spend. 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.

Hematology & Oncology Physician is a mid-sized specialty nationwide, with 11,215 enrolled providers across 54 states and an average of 847 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

1000 W CARSON ST # N18
Torrance, CA 90502

Provider Details

NPI 1003159427
Specialty Hematology & Oncology Physician
Credentials M.D.
Gender Female
NPI Issued 04/03/2013

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 Sarah Tomassetti, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$7.2K

Largest payer

Novartis Pharmaceuticals Corporation

Most common payment type

Consulting Fee

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 Sarah Tomassetti, M.D.. To verify Sarah Tomassetti, 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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

16
Total Claims
$506
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
20
Total Day Supply
573
Generic Drug Cost
$461

Patient Demographics

Average Patient Age
68.0 years
Avg HCC Risk Score
2.51

Hematology & Oncology Physician Overview

How Sarah Tomassetti, M.D. fits within the Hematology & Oncology Physician landscape nationally.

11,215
Hematology & Oncology Physician Providers in US
54
States with Hematology & Oncology Physician
847
Avg Claims per Provider

Sarah Tomassetti, M.D.'s 16 claims are below the specialty average of 847.

Nearby Hematology & Oncology Physician Providers in California

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

Compare Hematology & Oncology 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 Hematology & Oncology 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 Sarah Tomassetti, M.D.'s specialty?
Sarah Tomassetti, M.D. specializes in Hematology & Oncology Physician and practices in Torrance, California. Credentials: M.D..
How much does Sarah Tomassetti, M.D. prescribe under Medicare Part D?
In 2023, Sarah Tomassetti, M.D. wrote 16 Medicare Part D claims totaling $506 in drug costs for N/A beneficiaries.
Where is Sarah Tomassetti, M.D. located?
Sarah Tomassetti, M.D. is located at 1000 W CARSON ST # N18, Torrance, CA, 90502. Phone: (310) 745-2882.
What is Sarah Tomassetti, M.D.'s NPI number?
Sarah Tomassetti, M.D.'s National Provider Identifier (NPI) is 1003159427, issued on 04/03/2013.
How many Hematology & Oncology Physician providers are there in the US?
There are 11,215 Hematology & Oncology Physician providers across 54 states in the US. The average Hematology & Oncology Physician provider writes 847 Medicare Part D claims per year.
Does Sarah Tomassetti, M.D. accept Medicare?
Sarah Tomassetti, M.D. appears in CMS Medicare data with 16 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Sarah Tomassetti, M.D.'s credentials?
Sarah Tomassetti, M.D.'s NPI is 1003159427 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.
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

Compiled from official public sources by the PlainDoctor editorial team.