2026 NPPES data Internal Medicine Physician NPI 1417041765 MD
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MARSHA ARMSTRONG, MD

Internal Medicine Physician in LOS GATOS, California. 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
991
Medicare Part D claims · 58 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
90%
generic claims · 10% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: MARSHA ARMSTRONG, MD is a Internal Medicine Physician ([object Object]) practicing in LOS GATOS, California with a Medicare Part D prescribing footprint of 991 claims across 58 beneficiaries — 10% brand-name prescribing .

What stands out: MARSHA ARMSTRONG, MD filed 991 Medicare Part D claims in 2023 across LOS GATOS, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

MARSHA ARMSTRONG, 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).

MARSHA ARMSTRONG, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 10/03/2006

NPI 1417041765

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

991 64% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in California

How Internal Medicine Physician compares to other specialties among California providers

California providers

Internal Medicine Physician share within California

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

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).

MARSHA ARMSTRONG, MD is a Internal Medicine Physician provider practicing in LOS GATOS, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1417041765. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

MARSHA ARMSTRONG, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 777 KNOWLES DR, LOS GATOS, CA, 95032, with a listed phone of (408) 370-3611. NPI 1417041765 was issued on 10/03/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ARMSTRONG 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 991 prescription claims written by this provider, covering 58 Medicare beneficiaries and totaling roughly $47K in drug spend, split 10% brand-name and 90% generic by claim count, with an opioid prescribing rate of 1.7%. 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

777 KNOWLES DR
LOS GATOS, CA 95032

Provider Details

NPI 1417041765
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 10/03/2006

License & disciplinary context — California MBC 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 ~150K California medical licensees in 2023 — they are NOT specific to MARSHA ARMSTRONG, MD. To verify MARSHA ARMSTRONG, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC 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 California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

MARSHA ARMSTRONG, MD — brand share 10.0%
Specialty average (est.)

10% brand-name claims vs 90% generic, on 991 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.

991
Total Claims
$47K
Total Drug Cost
58
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,842
Total Day Supply
53,341
Brand vs Generic
10% brand / 90% generic
Brand Drug Cost
$28K
Generic Drug Cost
$19K
Opioid Claims
17 (1.7% rate)
Antibiotic Claims
53

Patient Demographics

Average Patient Age
80.1 years
Avg HCC Risk Score
0.99
Gender Split
74% female / 26% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Levothyroxine Sodium
56
Potassium Chloride
53
Allopurinol
39
Furosemide
37
Atorvastatin Calcium
34
Amitriptyline Hcl
27
Amlodipine Besylate
27
Gabapentin
27
Estradiol
26
Clopidogrel
Clopidogrel Bisulfate
25

* 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 MARSHA ARMSTRONG, 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

MARSHA ARMSTRONG, MD's 991 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in California

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

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

Frequently Asked Questions

What is MARSHA ARMSTRONG, MD's specialty?
MARSHA ARMSTRONG, MD specializes in Internal Medicine Physician and practices in LOS GATOS, California. Credentials: MD.
How much does MARSHA ARMSTRONG, MD prescribe under Medicare Part D?
In 2023, MARSHA ARMSTRONG, MD wrote 991 Medicare Part D claims totaling $47K in drug costs for 58 beneficiaries.
Where is MARSHA ARMSTRONG, MD located?
MARSHA ARMSTRONG, MD is located at 777 KNOWLES DR, LOS GATOS, CA, 95032. Phone: (408) 370-3611.
What is MARSHA ARMSTRONG, MD's NPI number?
MARSHA ARMSTRONG, MD's National Provider Identifier (NPI) is 1417041765, issued on 10/03/2006.
Does MARSHA ARMSTRONG, MD prescribe more brand-name or generic drugs?
MARSHA ARMSTRONG, MD's prescribing is 10% brand-name and 90% generic drugs by claim count, with $28K in brand drug costs.
Does MARSHA ARMSTRONG, MD prescribe opioids?
Yes, MARSHA ARMSTRONG, MD had 17 opioid claims in 2023 with an opioid prescribing rate of 1.7%.
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 MARSHA ARMSTRONG, MD prescribe most often?
Based on 2023 Medicare Part D data, MARSHA ARMSTRONG, MD's most frequently prescribed drugs include Levothyroxine Sodium, Potassium Chloride, Allopurinol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MARSHA ARMSTRONG, MD accept Medicare?
MARSHA ARMSTRONG, MD appears in CMS Medicare data with 991 Part D claims and 58 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MARSHA ARMSTRONG, MD's credentials?
MARSHA ARMSTRONG, MD's NPI is 1417041765 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