Diane C. Tsai, M.D.
Radiation Oncology Physician · Portland, OR
Diane C. Tsai, M.D. is a radiation oncology physician with a practice address in Portland, Oregon, and NPI 1730266966, issued on Nov 1, 2006. Check the license (Oregon MD174455, as entered in NPPES) on the Oregon Medical Board; the Medicare figures below come from public CMS files.
- Name
- Diane C. Tsai
- Credential
- M.D.
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License numbers
- MD174455 OR
G86931 CA
MD00037303 WA
Self-reported in NPPES; status is on the state search - Practice location
- 3620 N Interstate Ave, Portland, OR 97227
- Phone
- (503) 813-2000
- Enumerated
- Nov 1, 2006
- Record last updated
- Dec 9, 2025
- Medicare enrollment
- Enrolled (PECOS I20151002002628); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 115 in Oregon → Look up another NPI →
Also registered at 3620 N Interstate Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Thomas Johnson, M.D.Radiation Oncology Physician1083601835
- Vinayak Muralidhar, MDInternal Medicine Physician1811345655
- Jaishanker Nautiyal, M.D.Radiation Oncology Physician1043208820
- Aaron Sabolch, MDRadiation Oncology Physician1033402995
- Nina Scott, MSWCounselor1619213352
- Natasha Tobias-White, REGISTERED NURSEFamily Nurse Practitioner1700453222
Verify Diane C. Tsai in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersOregon Medical Board
Search for license MD174455Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
27% more Medicare Part D claims than the average radiation oncology physician in 2024
170 Medicare Part D claims for 67 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D.
Most prescribed
- Mupirocin35 claims
- Tamsulosin Hcl33 claims
- Cephalexin29 claims
- Nystatin13 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: $25.91
1 payment: food and beverage; the largest payer was Siemens Medical Solutions USA, Inc. The 3,275 providers of this specialty with any payment received $1,897.85 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.
6 hospitals and group practices
- Community Hospital OF The Monterey PeninsulaMonterey, CA · Acute Care Hospitals4 of 5 stars
- Bay Area Hospital DistrictCoos Bay, OR
- Kaiser Foundation Health Plan OF The NorthwestVancouver, WA
- PeacehealthBellingham, WA
- Portland Adventist Medical CenterPortland, OR
- Providence Health And Services - WashingtonWalla Walla, WA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through); hospitals matched to CMS Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.
Diane C. Tsai among 115 radiation oncology physician records in Oregon
Diane C. Tsai, 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 2006, is newer than 23% of them.
- NPI issued2006 · 23% of these records are older, 48% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 74% of these records are
- Graduated1991 · 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 Portland → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Kiri Cook, MDPortland, OR 972271003235110
- Nicolaas De Wette, M.D.Portland, OR 972271689677692
- Kathleen Jaffe, M.D., MPHPortland, OR 972271386031649
- Thomas Johnson, M.D.Portland, OR 972271083601835
- Jaishanker Nautiyal, M.D.Portland, OR 972271043208820
- Gregory Patton, M.D.Portland, OR 972271275536948
- Akanksha Rajeurs, M.D.Portland, OR 972271194110247
- Aaron Sabolch, MDPortland, OR 972271033402995
Common questions
What is Diane C. Tsai, M.D.'s NPI number?
Diane C. Tsai, M.D.'s National Provider Identifier (NPI) is 1730266966, issued on Nov 1, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Diane C. Tsai, M.D. located?
The NPPES record lists a practice address at 3620 N Interstate Ave, Portland, OR, 97227. Phone: (503) 813-2000. Providers update this record themselves, so call before visiting.
How can I verify Diane C. Tsai, M.D.'s license?
NPPES lists Oregon license number MD174455, 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 Diane C. Tsai, M.D. prescribe under Medicare Part D?
In 2024, Diane C. Tsai, M.D. had 170 Medicare Part D claims for 67 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.