2026 NPPES data Family Medicine Physician NPI 1528071883 MD
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MARLA ONISHI, MD

Family Medicine Physician in CAMBRIDGE, 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
67
Medicare Part D claims · 37 beneficiaries · Family Medicine Physician avg: 3K

What the federal data shows

MARLA ONISHI, MD filed 67 Medicare Part D claims in 2023 as a Family Medicine Physician in CAMBRIDGE, Massachusetts.

67
Part D claims, 2023
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.

MARLA ONISHI, MD's Medicare Part D volume vs every U.S. prescriber

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

67 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 certification likely (heuristic — not verified)

MARLA ONISHI, MD 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 MARLA ONISHI, MD?

Quality data not reported

NPI registry status

Active

Issued 08/15/2006

NPI 1528071883

Primary specialty

Family Medicine Physician

High-volume

147,640 US NPIs in this specialty

Medicare Part D claims

67 98% vs specialty avg

2023 prescription claims

Specialty avg: 3,418

Specialty distribution in Massachusetts

How Family Medicine Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Family Medicine Physician share within Massachusetts

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

Specialty board-certification context

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

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

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

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

MARLA ONISHI, MD appears in the CMS NPPES registry as a Family Medicine Physician provider holding MD credentials at 75 MOUNT AUBURN ST, CAMBRIDGE, MA, 02138, with a listed phone of (617) 495-2001. NPI 1528071883 was issued on 08/15/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ONISHI 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 67 prescription claims written by this provider, covering 37 Medicare beneficiaries and totaling roughly $1K 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.

Family Medicine Physician is a high-volume specialty nationwide, with 147,640 enrolled providers across 56 states and an average of 3,418 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

75 MOUNT AUBURN ST
CAMBRIDGE, MA 02138

Provider Details

NPI 1528071883
Specialty Family Medicine Physician
Credentials MD
Gender Female
NPI Issued 08/15/2006

Hospital and facility affiliations

Facilities where MARLA ONISHI, MD 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.

PRESIDENT AND FELLOWS OF HARVARD COLLEGE
CAMBRIDGE, MA

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 — 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 MARLA ONISHI, MD. To verify MARLA ONISHI, 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.

Medicare Part D Prescribing Data

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

67
Total Claims
$1K
Total Drug Cost
37
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
118
Total Day Supply
2,888
Generic Drug Cost
$923
Antibiotic Claims
11

Patient Demographics

Average Patient Age
78.1 years
Avg HCC Risk Score
1.07
Gender Split
43% female / 57% male

Family Medicine Physician Overview

How MARLA ONISHI, MD fits within the Family Medicine Physician landscape nationally.

147,640
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider

MARLA ONISHI, MD's 67 claims are below the specialty average of 3,418.

Nearby Family Medicine Physician Providers in Massachusetts

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

Compare Family Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is MARLA ONISHI, MD's specialty?
MARLA ONISHI, MD specializes in Family Medicine Physician and practices in CAMBRIDGE, Massachusetts. Credentials: MD.
How much does MARLA ONISHI, MD prescribe under Medicare Part D?
In 2023, MARLA ONISHI, MD wrote 67 Medicare Part D claims totaling $1K in drug costs for 37 beneficiaries.
Where is MARLA ONISHI, MD located?
MARLA ONISHI, MD is located at 75 MOUNT AUBURN ST, CAMBRIDGE, MA, 02138. Phone: (617) 495-2001.
What is MARLA ONISHI, MD's NPI number?
MARLA ONISHI, MD's National Provider Identifier (NPI) is 1528071883, issued on 08/15/2006.
How many Family Medicine Physician providers are there in the US?
There are 147,640 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
Does MARLA ONISHI, MD accept Medicare?
MARLA ONISHI, MD appears in CMS Medicare data with 67 Part D claims and 37 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MARLA ONISHI, MD's credentials?
MARLA ONISHI, MD's NPI is 1528071883 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