2026 NPPES data Internal Medicine Physician NPI 1437264512 MD
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SUSAN FELSENTHAL, MD

Internal Medicine Physician in CUDAHY, Wisconsin. 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
97
Medicare Part D claims · 19 beneficiaries · Internal Medicine Physician avg: 3K
What the federal data reveals: SUSAN FELSENTHAL, MD is a Internal Medicine Physician ([object Object]) practicing in CUDAHY, Wisconsin with a Medicare Part D prescribing footprint of 97 claims across 19 beneficiaries .

What stands out: SUSAN FELSENTHAL, MD filed 97 Medicare Part D claims in 2023 across CUDAHY, Wisconsin. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

SUSAN FELSENTHAL, 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).

SUSAN FELSENTHAL, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 08/20/2006

NPI 1437264512

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

97 96% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Wisconsin

How Internal Medicine Physician compares to other specialties among Wisconsin providers

Wisconsin providers

Internal Medicine Physician share within Wisconsin

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

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).

SUSAN FELSENTHAL, MD is a Internal Medicine Physician provider practicing in CUDAHY, Wisconsin, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1437264512. 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.

SUSAN FELSENTHAL, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 5900 S LAKE DR, CUDAHY, WI, 53110, with a listed phone of (414) 489-9000. NPI 1437264512 was issued on 08/20/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what FELSENTHAL 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 97 prescription claims written by this provider, covering 19 Medicare beneficiaries and totaling roughly $2K 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.

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

5900 S LAKE DR
CUDAHY, WI 53110

Provider Details

NPI 1437264512
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 08/20/2006

Medicare Part D Prescribing Data

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

97
Total Claims
$2K
Total Drug Cost
19
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
101
Total Day Supply
1,830
Generic Drug Cost
$810

Patient Demographics

Average Patient Age
54.6 years
Avg HCC Risk Score
1.45

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Hydrochlorothiazide
18
Amlodipine Besylate
16
Losartan Potassium
15

* 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 SUSAN FELSENTHAL, 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

SUSAN FELSENTHAL, MD's 97 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Wisconsin

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

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

Frequently Asked Questions

What is SUSAN FELSENTHAL, MD's specialty?
SUSAN FELSENTHAL, MD specializes in Internal Medicine Physician and practices in CUDAHY, Wisconsin. Credentials: MD.
How much does SUSAN FELSENTHAL, MD prescribe under Medicare Part D?
In 2023, SUSAN FELSENTHAL, MD wrote 97 Medicare Part D claims totaling $2K in drug costs for 19 beneficiaries.
Where is SUSAN FELSENTHAL, MD located?
SUSAN FELSENTHAL, MD is located at 5900 S LAKE DR, CUDAHY, WI, 53110. Phone: (414) 489-9000.
What is SUSAN FELSENTHAL, MD's NPI number?
SUSAN FELSENTHAL, MD's National Provider Identifier (NPI) is 1437264512, issued on 08/20/2006.
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 SUSAN FELSENTHAL, MD prescribe most often?
Based on 2023 Medicare Part D data, SUSAN FELSENTHAL, MD's most frequently prescribed drugs include Hydrochlorothiazide, Amlodipine Besylate, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does SUSAN FELSENTHAL, MD accept Medicare?
SUSAN FELSENTHAL, MD appears in CMS Medicare data with 97 Part D claims and 19 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify SUSAN FELSENTHAL, MD's credentials?
SUSAN FELSENTHAL, MD's NPI is 1437264512 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