2026 NPPES data Specialist NPI 1346217155 M.D.
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JOHN LAROSSA, M.D.

Specialist in NEWTON, Massachusetts. 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
3K
Medicare Part D claims · 372 beneficiaries · Specialist avg: 1K
Generic prescribing
71%
generic claims · 29% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

JOHN LAROSSA, M.D. filed 3,053 Medicare Part D claims in 2023 as a Specialist in NEWTON, Massachusetts, prescribing 71% generic.

3K
Part D claims, 2023
71%
generic prescribing

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.

JOHN LAROSSA, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

3,053 Top 11% higher than 89% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. 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

What does the federal data show about JOHN LAROSSA, M.D.?

Quality data not reported

NPI registry status

Active

Issued 03/01/2006

NPI 1346217155

Primary specialty

Specialist

High-volume

69,658 US NPIs in this specialty

Medicare Part D claims

3,053 107% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

Specialty distribution in Massachusetts

How Specialist compares to other specialties among Massachusetts providers

Massachusetts providers

Specialist share within Massachusetts

1. Specialist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Specialist share within Massachusetts

Specialty board-certification context

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

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

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

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

JOHN LAROSSA, M.D. appears in the CMS NPPES registry as a Specialist provider holding M.D. credentials at 2000 WASHINGTON ST, NEWTON, MA, 02462, with a listed phone of (617) 244-1311. NPI 1346217155 was issued on 03/01/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what LAROSSA 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 3,053 prescription claims written by this provider, covering 372 Medicare beneficiaries and totaling roughly $787K in drug spend, split 29% brand-name and 71% generic by claim count, with an opioid prescribing rate of 1.0%. 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.

Specialist is a high-volume specialty nationwide, with 69,658 enrolled providers across 55 states and an average of 1,474 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

2000 WASHINGTON ST
NEWTON, MA 02462

Provider Details

NPI 1346217155
Specialty Specialist
Credentials M.D.
Gender Male
NPI Issued 03/01/2006

License & disciplinary context — Massachusetts BORIM 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 ~38K Massachusetts medical licensees in 2023 — they are NOT specific to JOHN LAROSSA, M.D.. To verify JOHN LAROSSA, M.D.'s current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases

BORIM 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 Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Above average

JOHN LAROSSA, M.D. — brand share 29.0%
Specialty average (est.)

29% brand-name claims vs 71% generic, on 3,053 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.

3,053
Total Claims
$787K
Total Drug Cost
372
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
6,769
Total Day Supply
199,535
Brand vs Generic
29% brand / 71% generic
Brand Drug Cost
$715K
Generic Drug Cost
$64K
Opioid Claims
31 (1.0% rate)
Antibiotic Claims
24

Patient Demographics

Average Patient Age
76.6 years
Avg HCC Risk Score
1.10
Gender Split
62% female / 38% male
Age Distribution
<65: 12, 65-74: 146, 75-84: 148, 85+: 66

Top Prescribed Drugs (Medicare Part D)

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

What JOHN LAROSSA, M.D. 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
397
Jardiance
Empagliflozin
211
Metformin Hcl
160
Atorvastatin Calcium
141
Glipizide
138
Synthroid
Levothyroxine Sodium
89
Simvastatin
72
Trulicity
Dulaglutide
62
Liothyronine Sodium
58
Lisinopril
55

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

Specialist Overview

How JOHN LAROSSA, M.D. fits within the Specialist landscape nationally.

69,658
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider

JOHN LAROSSA, M.D.'s 3,053 claims are above the specialty average of 1,474.

Nearby Specialist Providers in Massachusetts

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

Compare Specialist nationally: see state-by-state distribution →

Frequently Asked Questions

What is JOHN LAROSSA, M.D.'s specialty?
JOHN LAROSSA, M.D. specializes in Specialist and practices in NEWTON, Massachusetts. Credentials: M.D..
How much does JOHN LAROSSA, M.D. prescribe under Medicare Part D?
In 2023, JOHN LAROSSA, M.D. wrote 3,053 Medicare Part D claims totaling $787K in drug costs for 372 beneficiaries.
Where is JOHN LAROSSA, M.D. located?
JOHN LAROSSA, M.D. is located at 2000 WASHINGTON ST, NEWTON, MA, 02462. Phone: (617) 244-1311.
What is JOHN LAROSSA, M.D.'s NPI number?
JOHN LAROSSA, M.D.'s National Provider Identifier (NPI) is 1346217155, issued on 03/01/2006.
Does JOHN LAROSSA, M.D. prescribe more brand-name or generic drugs?
JOHN LAROSSA, M.D.'s prescribing is 29% brand-name and 71% generic drugs by claim count, with $715K in brand drug costs.
Does JOHN LAROSSA, M.D. prescribe opioids?
Yes, JOHN LAROSSA, M.D. had 31 opioid claims in 2023 with an opioid prescribing rate of 1.0%.
How many Specialist providers are there in the US?
There are 69,658 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does JOHN LAROSSA, M.D. prescribe most often?
Based on 2023 Medicare Part D data, JOHN LAROSSA, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Jardiance, Metformin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOHN LAROSSA, M.D. accept Medicare?
JOHN LAROSSA, M.D. appears in CMS Medicare data with 3,053 Part D claims and 372 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOHN LAROSSA, M.D.'s credentials?
JOHN LAROSSA, M.D.'s NPI is 1346217155 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