NPPES file of Aug 9, 2026

Hassan I. Tahsildar, M.D.

Medical Oncology Physician · Green Bay, WI

Hassan I. Tahsildar, M.D. is a medical oncology physician with a practice address in Green Bay, Wisconsin, and NPI 1629067269, issued on Oct 17, 2005. Check the license (Wisconsin 54846-020, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1629067269
Name
Hassan I. Tahsildar
Credential
M.D.
Primary taxonomy
Medical Oncology Physician 207RX0202X
License number
54846-020 WI
Self-reported in NPPES; status is on the state search
Practice location
1580 Commanche Ave, Green Bay, WI 54313
Phone
(920) 435-8326
Enumerated
Oct 17, 2005
Record last updated
Jan 14, 2021 (not updated in 5 years: call before relying on the address or phone)
Medicare enrollment
Enrolled (PECOS I20101207001253); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest medical oncology physician records → All 69 in Wisconsin → Look up another NPI →

Also registered at 1580 Commanche Ave

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Sara Aerts, NPAdult Health Nurse Practitioner1750628970
  2. Cynthia Bieda, APNPFamily Nurse Practitioner1316518533
  3. Collin Bowman, M.D.Hospice and Palliative Medicine (Family Medicine) Physician1922462092
  4. Anjali Budhathoki, M.DHematology & Oncology Physician1548558166
  5. Mary Connelly, MDFamily Medicine Physician1841274636
  6. Jani Cook, NPFamily Nurse Practitioner1841714979

Verify Hassan I. Tahsildar in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWisconsin Medical Examining Board
    Search for license 54846-020    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Wisconsin license search

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66% more Medicare Part D claims than the average medical oncology physician in 2024

1,165 Medicare Part D claims for 196 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. Brand-name drugs were 29% of claims. 53 claims were for opioids.

  1. Hassan Tahsildar1,165
  2. Specialty average703

Most prescribed

  1. Anastrozole149 claims
  2. Imbruvica119 claims
  3. Acyclovir76 claims
  4. Ondansetron Hcl61 claims
  5. Prochlorperazine Maleate47 claims
  6. Lenalidomide43 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: $18.99

1 payment: food and beverage; the largest payer was Jazz Pharmaceuticals Inc. The 3,343 providers of this specialty with any payment received $11,773.47 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Hassan Tahsildar$19
  2. Specialty average$11,773

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through 2 group practices

  1. Bellin Memorial Hospital IncGreen Bay, WI
  2. Oconto Hospital And Medical Center IncMarinette, WI

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Hassan I. Tahsildar among 69 medical oncology physician records in Wisconsin

Hassan I. Tahsildar, M.D. is one of 69 medical oncology physician records with a practice address in Wisconsin. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.

  • NPI issued2005 · 0% of these records are older, 90% newer
  • In a Medicare fileYes · 74% of these records are
  • In the CMS Doctors and Clinicians fileYes · 67% of these records are
  • Graduated1985 · median 2001 among the 46 with a school on file
  • Record last updated2021 · 59% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RX0202X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Medical Oncology Physician providers in Wisconsin

There are 69 medical oncology physician records in Wisconsin.

All 69 in Wisconsin → Every provider in Green Bay → Medical Oncology Physician nationwide →

The 8 medical oncology physician records with the nearest ZIP codes

  1. Maria De Villa, M.D.Green Bay, WI 543131538321252
  2. James McGovern, M.D.Green Bay, WI 543111053447672
  3. Kamal Kant Singh Abbi, M.D.Green Bay, WI 543031588827778
  4. David Groteluschen, M.D.Green Bay, WI 543031679538011
  5. Thomas Saphner, M.D.Green Bay, WI 543031700970894
  6. Alexander Starr, MDGreen Bay, WI 543031790722619
  7. Ruth Warren, DOGreen Bay, WI 543031124096185
  8. Evan WenigGreen Bay, WI 543031215460068

Common questions

What is Hassan I. Tahsildar, M.D.'s NPI number?

Hassan I. Tahsildar, M.D.'s National Provider Identifier (NPI) is 1629067269, issued on Oct 17, 2005. An NPI identifies a provider in billing; it is not a license.

Where is Hassan I. Tahsildar, M.D. located?

The NPPES record lists a practice address at 1580 Commanche Ave, Green Bay, WI, 54313. Phone: (920) 435-8326. Providers update this record themselves, so call before visiting.

How can I verify Hassan I. Tahsildar, M.D.'s license?

NPPES lists Wisconsin license number 54846-020, as entered by the provider. Search the Wisconsin Medical Examining Board at https://dsps.wi.gov/Pages/BoardsCouncils/MEB/Default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Hassan I. Tahsildar, M.D. prescribe under Medicare Part D?

In 2024, Hassan I. Tahsildar, M.D. had 1,165 Medicare Part D claims for 196 beneficiaries; the average among medical oncology physician prescribers was 703. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.