2026 NPPES data Pediatric Hematology & Oncology Physician NPI 1851534481 M.D., M.P.H.
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Stephanie Massaro, M.D., M.P.H.

Pediatric Hematology & Oncology Physician in New Haven, Connecticut.

This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 2,568 in Pediatric 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.
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Stephanie Massaro, M.D., M.P.H. is a Pediatric Hematology & Oncology Physician in New Haven, Connecticut, 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)

Stephanie Massaro, M.D., M.P.H. 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 Stephanie Massaro, M.D., M.P.H.?

Quality data not reported

NPI registry status

Active

Issued 04/13/2009

NPI 1851534481

Primary specialty

Pediatric Hematology & Oncology Physician

Niche

2,568 US NPIs in this specialty

Specialty distribution in Connecticut

How Pediatric Hematology & Oncology Physician compares to other specialties among Connecticut providers

Connecticut providers
Clinical Social Worker - 8.4%Clinical Social Worker8.4%Student in an Organized Health Care Education/Training Program - 7.7%Student in an Organized Health Care Education/Training Program7.7%Physical Therapist - 4.2%Physical Therapist4.2%Pharmacist - 3.9%Pharmacist3.9%Internal Medicine Physician - 3.4%Internal Medicine Physician3.4%Mental Health Counselor - 3.2%Mental Health Counselor3.2%Pediatric Hematology & Oncology Physician - 0%Pediatric Hematology & Oncology Physician0%
Largest specialties in Connecticut (% of in-state providers)

Board certification

Not published by CMS

CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Pediatric Hematology & Oncology Physician. Verify directly:

How MIPS and board certification work

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).

Stephanie Massaro, M.D., M.P.H. appears in the CMS NPPES registry as a Pediatric Hematology & Oncology Physician provider holding M.D., M.P.H. credentials at 333 CEDAR ST, New Haven, CT, 06520, with a listed phone of (203) 785-4640. NPI 1851534481 was issued on 04/13/2009.

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 Pediatric Hematology & Oncology Physician providers operate outside Part D entirely.

Pediatric Hematology & Oncology Physician is a narrow specialty nationwide, with 2,568 enrolled providers across 52 states and an average of 92 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

333 CEDAR ST
New Haven, CT 06520

Provider Details

NPI 1851534481
Specialty Pediatric Hematology & Oncology Physician
Credentials M.D., M.P.H.
Gender Female
NPI Issued 04/13/2009

Hospital and facility affiliations

Facilities where Stephanie Massaro, M.D., M.P.H. 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.

Yale University
Trumbull, CT

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Pediatric Hematology & Oncology Physician Overview

How Stephanie Massaro, M.D., M.P.H. fits within the Pediatric Hematology & Oncology Physician landscape nationally.

2,568
Pediatric Hematology & Oncology Physician Providers in US
52
States with Pediatric Hematology & Oncology Physician
92
Avg Claims per Provider

Nearby Pediatric Hematology & Oncology Physician Providers in Connecticut

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

Compare Pediatric 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 Connecticut medical board, federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Pediatric 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 Stephanie Massaro, M.D., M.P.H.'s specialty?
Stephanie Massaro, M.D., M.P.H. specializes in Pediatric Hematology & Oncology Physician and practices in New Haven, Connecticut. Credentials: M.D., M.P.H..
Where is Stephanie Massaro, M.D., M.P.H. located?
Stephanie Massaro, M.D., M.P.H. is located at 333 CEDAR ST, New Haven, CT, 06520. Phone: (203) 785-4640.
What is Stephanie Massaro, M.D., M.P.H.'s NPI number?
Stephanie Massaro, M.D., M.P.H.'s National Provider Identifier (NPI) is 1851534481, issued on 04/13/2009.
How many Pediatric Hematology & Oncology Physician providers are there in the US?
There are 2,568 Pediatric Hematology & Oncology Physician providers across 52 states in the US. The average Pediatric Hematology & Oncology Physician provider writes 92 Medicare Part D claims per year.
Does Stephanie Massaro, M.D., M.P.H. accept Medicare?
Stephanie Massaro, M.D., M.P.H. appears in CMS Medicare data. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Stephanie Massaro, M.D., M.P.H.'s credentials?
Stephanie Massaro, M.D., M.P.H.'s NPI is 1851534481 with credentials M.D., M.P.H.. 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

View source datasets and methodology notes
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.