Gregory S. Willis, M.D.
Radiation Oncology Physician · Tualatin, OR
Gregory S. Willis, M.D. is a radiation oncology physician with a practice address in Tualatin, Oregon, and NPI 1417941600, issued on Sep 2, 2005. Check the license (Oregon MD28019, as entered in NPPES) on the Oregon Medical Board; the Medicare figures below come from public CMS files.
- Name
- Gregory S. Willis
- Credential
- M.D.
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License numbers
- MD28019 OR
MD2016-0015 NM
Self-reported in NPPES; status is on the state search - Practice location
- 6489 SW Borland RD, Tualatin, OR 97062
- Phone
- (503) 692-4843
- Enumerated
- Sep 2, 2005
- Record last updated
- Jul 31, 2025
- Fax
- (503) 692-6543
- Medicare enrollment
- Enrolled (PECOS I20160506000139); accepts Medicare assignment
- Medical or professional school
- Oregon Health Sciences University School Of Medicine, 1999
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 115 in Oregon → Look up another NPI →
Verify Gregory S. Willis in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersOregon Medical Board
Search for license MD28019Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average radiation oncology physician in 2024
43 Medicare Part D claims for 24 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D.
Most prescribed
- Tamsulosin Hcl14 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.
Bills Medicare through one group practice
- Otero County Hospital AssociationAlamogordo, NM
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gregory S. Willis among 115 radiation oncology physician records in Oregon
Gregory S. Willis, M.D. is one of 115 radiation oncology physician records with a practice address in Oregon. 77% 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, 77% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 74% of these records are
- Graduated1999 · median 2006 among the 85 with a school on file
- Record last updated2025 · 50% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a Oregon practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in Oregon
There are 115 radiation oncology physician records in Oregon.
All 115 in Oregon → Every provider in Tualatin → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Keith Stelzer, M.D., PH.D.The Dalles, OR 970581881682573
- Grant Harmon, MDGresham, OR 970301639606379
- Kathryn Panwala, M.D.Gresham, OR 970301972591618
- Margaret Thompson, M.D.Amity, OR 971011982702221
- Pehr Hartvigson, MDAstoria, OR 971031750700498
- Jerald Albrich, M.D.Canby, OR 970131952467607
- Timur Mitin, M.D., PH.D.Hillsboro, OR 971231679745822
- Aasheeshraj Kanwar, M.D.McMinnville, OR 971281861925778
Common questions
What is Gregory S. Willis, M.D.'s NPI number?
Gregory S. Willis, M.D.'s National Provider Identifier (NPI) is 1417941600, issued on Sep 2, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Gregory S. Willis, M.D. located?
The NPPES record lists a practice address at 6489 SW Borland RD, Tualatin, OR, 97062. Phone: (503) 692-4843. Providers update this record themselves, so call before visiting.
How can I verify Gregory S. Willis, M.D.'s license?
NPPES lists Oregon license number MD28019, as entered by the provider. Search the Oregon Medical Board at https://www.oregon.gov/OMB/Pages/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gregory S. Willis, M.D. prescribe under Medicare Part D?
In 2024, Gregory S. Willis, M.D. had 43 Medicare Part D claims for 24 beneficiaries; the average among radiation oncology physician prescribers was 134. 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.