2026 NPPES data Internal Medicine Physician NPI 1043360928 M.D.
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Naomi Ko, M.D.

Internal Medicine Physician in Boston, Massachusetts.

This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 172,737 in Internal Medicine 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
136
Medicare Part D claims · 44 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

Naomi Ko, M.D. filed 136 Medicare Part D claims in 2023 as an Internal Medicine Physician in Boston, Massachusetts, prescribing 87% generic.

136
Part D claims, 2023
87%
generic prescribing
≥35th
pct by Part D claim volume (lower-bound band)

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.

Naomi Ko, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

136 ≥ 35th percentile 35% of 1,370,886 prescribers are in lower value bands

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. 2K+: 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.

The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board-eligible specialty (heuristic, not verified)

Naomi Ko, 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 Naomi Ko, M.D.?

Quality data not reported

NPI registry status

Active

Issued 01/11/2007

NPI 1043360928

Primary specialty

Internal Medicine Physician

High-volume

172,737 US NPIs in this specialty

Medicare Part D claims

136 95% 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
Mental Health Counselor8.3%Clinical Social Worker7.8%Student in an Organized Heal…6.2%Behavior Technician4.9%Counselor4.3%Internal Medicine Physician3.7%
Largest specialties in Massachusetts (% 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 Internal Medicine 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).

Naomi Ko, M.D. appears in the CMS NPPES registry as an Internal Medicine Physician provider holding M.D. credentials at 830 HARRISON AVE, Boston, MA, 02118, with a listed phone of (617) 638-6428. NPI 1043360928 was issued on 01/11/2007.

Medicare Part D records for calendar year 2023 show 136 prescription claims written by this provider, covering 44 Medicare beneficiaries and totaling roughly $304K in drug spend, split 13% brand-name and 87% generic by claim count.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,737 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

830 HARRISON AVE
Boston, MA 02118

Provider Details

NPI 1043360928
Specialty Internal Medicine Physician
Credentials M.D.
Gender Female
NPI Issued 01/11/2007

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 Naomi Ko, M.D.. To verify Naomi Ko, 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 · Typical

Naomi Ko, M.D. - brand share 13.0%
Internal Medicine Physician average

13% brand-name claims vs 87% generic, on 136 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.

136
Total Claims
$304K
Total Drug Cost
44
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
275
Total Day Supply
7,669
Brand vs Generic
13% brand / 87% generic
Brand Drug Cost
$297K
Generic Drug Cost
$7K

Patient Demographics

Average Patient Age
69.8 years
Avg HCC Risk Score
1.50

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Letrozole
78
Verzenio
Abemaciclib
13

* 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 Naomi Ko, M.D. fits within the Internal Medicine Physician landscape nationally.

172,737
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

Naomi Ko, M.D.'s 136 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 Ko.

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 Naomi Ko, M.D.'s specialty?
Naomi Ko, M.D. specializes in Internal Medicine Physician and practices in Boston, Massachusetts. Credentials: M.D..
How much does Naomi Ko, M.D. prescribe under Medicare Part D?
In 2023, Naomi Ko, M.D. wrote 136 Medicare Part D claims totaling $304K in drug costs for 44 beneficiaries.
Where is Naomi Ko, M.D. located?
Naomi Ko, M.D. is located at 830 HARRISON AVE, Boston, MA, 02118. Phone: (617) 638-6428.
What is Naomi Ko, M.D.'s NPI number?
Naomi Ko, M.D.'s National Provider Identifier (NPI) is 1043360928, issued on 01/11/2007.
Does Naomi Ko, M.D. prescribe more brand-name or generic drugs?
Naomi Ko, M.D.'s prescribing is 13% brand-name and 87% generic drugs by claim count, with $297K in brand drug costs.
How many Internal Medicine Physician providers are there in the US?
There are 172,737 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 Naomi Ko, M.D. prescribe most often?
Based on 2023 Medicare Part D data, Naomi Ko, M.D.'s most frequently prescribed drugs include Letrozole, Verzenio. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Naomi Ko, M.D. accept Medicare?
Naomi Ko, M.D. appears in CMS Medicare data with 136 Part D claims and 44 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Naomi Ko, M.D.'s credentials?
Naomi Ko, M.D.'s NPI is 1043360928 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

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.
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

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.