Marsha Horwitz, M.D.
Neurology Physician · Dubuque, IA
Marsha Horwitz, M.D. is a neurology physician with a practice address in Dubuque, Iowa, and NPI 1992757553, issued on May 16, 2006. Check the license (Iowa 33757, as entered in NPPES) on the Iowa Board of Medicine; the Medicare figures below come from public CMS files.
- Name
- Marsha Horwitz
- Credential
- M.D.
- Primary taxonomy
- Neurology Physician 2084N0400X
- License numbers
- 33757 IA
48570 WI
Self-reported in NPPES; status is on the state search - Practice location
- 1000 Langworthy St, Dubuque, IA 52001
- Phone
- (563) 584-3495
- Enumerated
- May 16, 2006
- Record last updated
- Jan 12, 2011 (not updated in 15 years: call before relying on the address or phone)
- Fax
- (563) 584-3395
- Medicaid ID
- 0217026 IA
- Entity
- Type 1 · individual
8 nearest neurology physician records → All 167 in Iowa → Look up another NPI →
Also registered at 1000 Langworthy St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Louis Alt, M.D.Otolaryngology Physician1902855778
- Courtney Ambrosy, PA-CPhysician Assistant1457121345
- Sarah ArnoldMedical Physician Assistant1558016113
- Paula Aston, MDNeurology Physician1144286675
- Kala Ave-Lallemant, FNPFamily Nurse Practitioner1235551656
- Martin Bagby, DOFamily Medicine Physician1942269402
Verify Marsha Horwitz in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIowa Board of Medicine
Search for license 33757Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
93% fewer Medicare Part D claims than the average neurology physician in 2024
98 Medicare Part D claims for 23 beneficiaries, against an average of 1,370 among the 15,005 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Most prescribed
- Lamotrigine12 claims
- Topiramate12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $33.40
1 payment: food and beverage; the largest payer was Argenx US, Inc. The 10,858 providers of this specialty with any payment received $8,318.07 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Marsha Horwitz among 167 neurology physician records in Iowa
Marsha Horwitz, M.D. is one of 167 neurology physician records with a practice address in Iowa. 70% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 20% of them.
- NPI issued2006 · 20% of these records are older, 56% newer
- In a Medicare fileYes · 70% of these records are
- In the CMS Doctors and Clinicians fileNo · 51% of these records are
- Record last updated2011 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084N0400X and a Iowa practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Neurology Physician providers in Iowa
There are 167 neurology physician records in Iowa.
All 167 in Iowa → Every provider in Dubuque → Neurology Physician nationwide →
The 8 neurology physician records with the nearest ZIP codes
- Paula Aston, MDDubuque, IA 520011144286675
- Preeti Joseph, MDDubuque, IA 520011730229121
- Mark Fortson, M.D.Dubuque, IA 520021467413914
- Ronald Sims, M.D.Dubuque, IA 520021639138837
- Patrick Sterrett, M.D., PH.D.Dubuque, IA 520031922078500
- Dana Ghazaleh, MDCoralville, IA 522411053047258
- Harold Adams, MDIowa City, IA 522421396737912
- Edward Aul, MDIowa City, IA 522421538151105
Common questions
What is Marsha Horwitz, M.D.'s NPI number?
Marsha Horwitz, M.D.'s National Provider Identifier (NPI) is 1992757553, issued on May 16, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Marsha Horwitz, M.D. located?
The NPPES record lists a practice address at 1000 Langworthy St, Dubuque, IA, 52001. Phone: (563) 584-3495. Providers update this record themselves, so call before visiting.
How can I verify Marsha Horwitz, M.D.'s license?
NPPES lists Iowa license number 33757, as entered by the provider. Search the Iowa Board of Medicine at https://dial.iowa.gov/about-dial/boards-and-commissions/medicine. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Marsha Horwitz, M.D. prescribe under Medicare Part D?
In 2024, Marsha Horwitz, M.D. had 98 Medicare Part D claims for 23 beneficiaries; the average among neurology physician prescribers was 1,370. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.