2026 NPPES data Internal Medicine Physician NPI 1366539934 MD
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Cecilia Larson, MD

Internal Medicine Physician in Needham, 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
526
Medicare Part D claims · 107 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
50%
generic claims · 50% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

Cecilia Larson, MD filed 526 Medicare Part D claims in 2023 as a Internal Medicine Physician in Needham, Massachusetts, prescribing 50% generic.

526
Part D claims, 2023
50%
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.

Cecilia Larson, MD's Medicare Part D volume vs every U.S. prescriber

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

526 Top 34% higher than 66% 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%). This entry sits in this band. 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)

Cecilia Larson, MD 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 Cecilia Larson, MD?

Quality data not reported

NPI registry status

Active

Issued 10/06/2006

NPI 1366539934

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

526 81% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Massachusetts

How Internal Medicine Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Internal Medicine Physician share within Massachusetts

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

Specialty board-certification context

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

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

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

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

Cecilia Larson, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 148 CHESTNUT ST, Needham, MA, 02492, with a listed phone of (781) 453-5231. NPI 1366539934 was issued on 10/06/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Larson 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 526 prescription claims written by this provider, covering 107 Medicare beneficiaries and totaling roughly $248K in drug spend, split 50% brand-name and 50% 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.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

148 CHESTNUT ST
Needham, MA 02492

Provider Details

NPI 1366539934
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 10/06/2006

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 Cecilia Larson, MD. To verify Cecilia Larson, MD'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 · Brand-heavy

Cecilia Larson, MD — brand share 50.0%
Specialty average (est.)

50% brand-name claims vs 50% generic, on 526 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.

526
Total Claims
$248K
Total Drug Cost
107
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,145
Total Day Supply
34,052
Brand vs Generic
50% brand / 50% generic
Brand Drug Cost
$240K
Generic Drug Cost
$6K

Patient Demographics

Average Patient Age
75.7 years
Avg HCC Risk Score
1.56
Gender Split
64% female / 36% male

Top Prescribed Drugs (Medicare Part D)

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

What Cecilia Larson, MD 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
Trulicity
Dulaglutide
69
Levothyroxine Sodium
35
Metformin Hcl Er
Metformin Hcl
31
Jardiance
Empagliflozin
23
Metformin Hcl
21
Pioglitazone Hcl
21
Glipizide Er
Glipizide
20
Farxiga
Dapagliflozin Propanediol
18
Glipizide
18
Alendronate Sodium
17

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

Internal Medicine Physician Overview

How Cecilia Larson, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

Cecilia Larson, MD's 526 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Massachusetts

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

Compare Internal Medicine 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 Massachusetts medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Internal Medicine 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 Cecilia Larson, MD's specialty?
Cecilia Larson, MD specializes in Internal Medicine Physician and practices in Needham, Massachusetts. Credentials: MD.
How much does Cecilia Larson, MD prescribe under Medicare Part D?
In 2023, Cecilia Larson, MD wrote 526 Medicare Part D claims totaling $248K in drug costs for 107 beneficiaries.
Where is Cecilia Larson, MD located?
Cecilia Larson, MD is located at 148 CHESTNUT ST, Needham, MA, 02492. Phone: (781) 453-5231.
What is Cecilia Larson, MD's NPI number?
Cecilia Larson, MD's National Provider Identifier (NPI) is 1366539934, issued on 10/06/2006.
Does Cecilia Larson, MD prescribe more brand-name or generic drugs?
Cecilia Larson, MD's prescribing is 50% brand-name and 50% generic drugs by claim count, with $240K in brand drug costs.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Cecilia Larson, MD prescribe most often?
Based on 2023 Medicare Part D data, Cecilia Larson, MD's most frequently prescribed drugs include Trulicity, Levothyroxine Sodium, Metformin Hcl Er. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Cecilia Larson, MD accept Medicare?
Cecilia Larson, MD appears in CMS Medicare data with 526 Part D claims and 107 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Cecilia Larson, MD's credentials?
Cecilia Larson, MD's NPI is 1366539934 with credentials MD. 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