NPI registry status
Active
2026 NPPES data Radiation Oncology Physician NPI 1730266966 M.D.
Verify on CMS → Diane Tsai, M.D.
Radiation Oncology Physician in Portland, Oregon.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 6,029 in Radiation Oncology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
140
Medicare Part D claims · 66 beneficiaries · Radiation Oncology Physician avg: 186
Industry payments
$25.91
1 payments · CMS Open Payments (Sunshine Act)
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Diane Tsai, M.D. filed 140 Medicare Part D claims in 2023 as a Radiation Oncology Physician in Portland, Oregon.
- 140
- Part D claims, 2023
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Diane Tsai, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
140 35th percentile higher than 35% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
Diane Tsai, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 7 hospital affiliations - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Diane Tsai, M.D.?
Quality data not reportedPrimary specialty
Radiation Oncology Physician
Medicare Part D claims
140 25% vs specialty avg
Specialty distribution in Oregon
How Radiation Oncology Physician compares to other specialties among Oregon providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Radiation Oncology Physician. Verify directly:
How MIPS and board certification work
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).
Diane Tsai, M.D. appears in the CMS NPPES registry as a Radiation Oncology Physician provider holding M.D. credentials at 3620 N INTERSTATE AVE, Portland, OR, 97227, with a listed phone of (503) 813-2000. NPI 1730266966 was issued on 11/01/2006.
Medicare Part D records for calendar year 2023 show 140 prescription claims written by this provider, covering 66 Medicare beneficiaries and totaling roughly $3K in drug spend.
Radiation Oncology Physician is a mid-sized specialty nationwide, with 6,029 enrolled providers across 53 states and an average of 186 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
Provider Details
| NPI | 1730266966 |
|---|---|
| Specialty | Radiation Oncology Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 11/01/2006 |
Hospital and facility affiliations
Facilities where Diane Tsai, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
According to CMS billing records, Diane Tsai, M.D. is affiliated with 7 Medicare-billing facilities across 4 states, 1 of which carry a CMS Hospital overall star rating.
Community Hospital OF The Monterey Peninsula
★★★★☆ 4/5
Monterey, CA
Acute Care Hospitals
CMS CCN: 050145
Alii Health Center
Kailua Kona, HI
Bay Area Hospital District
Coos Bay, OR
Kaiser Foundation Health Plan OF The Northwest
Vancouver, WA
Peacehealth
Bellingham, WA
Portland Adventist Medical Center
Portland, OR
Providence Health And Services - Washington
Walla Walla, WA
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Industry payments received (2024) - CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Diane Tsai, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$26
Largest payer
Siemens Medical Solutions USA, Inc.
Most common payment type
Food and Beverage
Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
140
Total Claims
$3K
Total Drug Cost
66
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 179
- Total Day Supply
- 3,799
- Generic Drug Cost
- $3K
- Antibiotic Claims
- 14
Patient Demographics
- Average Patient Age
- 72.8 years
- Avg HCC Risk Score
- 1.87
- Gender Split
- 44% female / 56% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Diane Tsai, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Tamsulosin Hcl
Tamsulosin Hcl
30 claims
- Ondansetron Odt
Ondansetron Odt
15 claims
- Lidocaine Hcl Visc…
Lidocaine Hcl Viscous
14 claims
- Mupirocin
Mupirocin
13 claims
- Cephalexin
Cephalexin
12 claims
| Drug | Claims |
|---|---|
| Tamsulosin Hcl | 30 |
| Ondansetron Odt Ondansetron | 15 |
| Lidocaine Hcl Viscous Lidocaine Hcl | 14 |
| Mupirocin | 13 |
| Cephalexin | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Radiation Oncology Physician Overview
How Diane Tsai, M.D. fits within the Radiation Oncology Physician landscape nationally.
6,029
Radiation Oncology Physician Providers in US
53
States with Radiation Oncology Physician
186
Avg Claims per Provider
Diane Tsai, M.D.'s 140 claims are below the specialty average of 186.
Nearby Radiation Oncology Physician Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Tsai.
Dr. Bradley Ackerson
MD
Portland, OR
Dr. Jerald Albrich
M.D.
Canby, OR
Dr. Lauren Andring
MD
Bend, OR
Dr. William Arscott
MD
Tigard, OR
Dr. Mary Austin-Seymour
M.D.
Corvallis, OR
Compare Radiation Oncology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Oregon medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Radiation Oncology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Diane Tsai, M.D.'s specialty? ▼
Diane Tsai, M.D. specializes in Radiation Oncology Physician and practices in Portland, Oregon. Credentials: M.D..
How much does Diane Tsai, M.D. prescribe under Medicare Part D? ▼
In 2023, Diane Tsai, M.D. wrote 140 Medicare Part D claims totaling $3K in drug costs for 66 beneficiaries.
Where is Diane Tsai, M.D. located? ▼
Diane Tsai, M.D. is located at 3620 N INTERSTATE AVE, Portland, OR, 97227. Phone: (503) 813-2000.
What is Diane Tsai, M.D.'s NPI number? ▼
Diane Tsai, M.D.'s National Provider Identifier (NPI) is 1730266966, issued on 11/01/2006.
How many Radiation Oncology Physician providers are there in the US? ▼
There are 6,029 Radiation Oncology Physician providers across 53 states in the US. The average Radiation Oncology Physician provider writes 186 Medicare Part D claims per year.
What drugs does Diane Tsai, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Diane Tsai, M.D.'s most frequently prescribed drugs include Tamsulosin Hcl, Ondansetron Odt, Lidocaine Hcl Viscous. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Diane Tsai, M.D. accept Medicare? ▼
Diane Tsai, M.D. appears in CMS Medicare data with 140 Part D claims and 66 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Diane Tsai, M.D.'s credentials? ▼
Diane Tsai, M.D.'s NPI is 1730266966 with credentials M.D.. 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
View source datasets and methodology notes
- 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
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.