NPI registry status
Active
2026 NPPES data Rheumatology Physician NPI 1215035670 M.D.
Verify on CMS → Esther Hwang, M.D.
Rheumatology 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 6,181 in Rheumatology 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
2K
Medicare Part D claims · 279 beneficiaries · Rheumatology Physician avg: 2K
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Esther Hwang, M.D. filed 1,506 Medicare Part D claims in 2023 as a Rheumatology Physician in Portland, Oregon.
- 2K
- 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.
Esther Hwang, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,506 Top 19% higher than 81% 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)
Esther Hwang, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 2 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 Esther Hwang, M.D.?
Quality data not reportedPrimary specialty
Rheumatology Physician
Medicare Part D claims
1,506 27% vs specialty avg
Specialty distribution in Oregon
How Rheumatology 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 Rheumatology 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).
Esther Hwang, M.D. appears in the CMS NPPES registry as a Rheumatology Physician provider holding M.D. credentials at 3550 N INTERSTATE AVE, Portland, OR, 97227, with a listed phone of (800) 813-2000. NPI 1215035670 was issued on 09/20/2006.
Medicare Part D records for calendar year 2023 show 1,506 prescription claims written by this provider, covering 279 Medicare beneficiaries and totaling roughly $1.2 million in drug spend.
Rheumatology Physician is a mid-sized specialty nationwide, with 6,181 enrolled providers across 52 states and an average of 2,054 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 | 1215035670 |
|---|---|
| Specialty | Rheumatology Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 09/20/2006 |
Hospital and facility affiliations
Facilities where Esther Hwang, 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.
Kaiser Foundation Health Plan OF The Northwest
Portland, OR
The Vancouver Clinic Inc PS
Vancouver, 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).
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,506
Total Claims
$1.2M
Total Drug Cost
279
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 3,497
- Total Day Supply
- 102,495
- Generic Drug Cost
- $51K
Patient Demographics
- Average Patient Age
- 73.9 years
- Avg HCC Risk Score
- 1.62
- Gender Split
- 70% female / 30% male
- Age Distribution
- <65: 28, 65-74: 121, 75-84: 100, 85+: 30
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Esther Hwang, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Methotrexate
Methotrexate
314 claims
- Prednisone
Prednisone
248 claims
- Hydroxychloroquine…
Hydroxychloroquine Sulfate
224 claims
- Allopurinol 112
Allopurinol
112 claims
- Folic Acid 98
Folic Acid
98 claims
- Alendronate Sodium 66
Alendronate Sodium
66 claims
- Sulfasalazine 62
Sulfasalazine
62 claims
- Humira(Cf) Pen 56
Humira(Cf) Pen
56 claims
| Drug | Claims |
|---|---|
| Methotrexate Methotrexate Sodium | 314 |
| Prednisone | 248 |
| Hydroxychloroquine Sulfate | 224 |
| Allopurinol | 112 |
| Folic Acid | 98 |
| Alendronate Sodium | 66 |
| Sulfasalazine | 62 |
| Humira(Cf) Pen Adalimumab | 56 |
| Colchicine | 36 |
| Azathioprine | 29 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Rheumatology Physician Overview
How Esther Hwang, M.D. fits within the Rheumatology Physician landscape nationally.
6,181
Rheumatology Physician Providers in US
52
States with Rheumatology Physician
2,054
Avg Claims per Provider
Esther Hwang, M.D.'s 1,506 claims are below the specialty average of 2,054.
Nearby Rheumatology Physician Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Hwang.
Dr. Alfredo Aguirre
M.D.
Portland, OR
Dr. Elizabeth Anderson
MD
Portland, OR
Dr. Kathryn Baker
DO
Portland, OR
Dr. Andre Barkhuizen
M.D.
Portland, OR
Dr. Jennifer Barton
M.D.
Portland, OR
Compare Rheumatology 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 Rheumatology 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.
Healthcare Guides
Learn more about finding, verifying, and understanding healthcare providers.
How to Find a Doctor
Step-by-step guide to choosing a provider
Verify Credentials
Check NPI, board certification & license status
Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore Oregon
Frequently Asked Questions
What is Esther Hwang, M.D.'s specialty? ▼
Esther Hwang, M.D. specializes in Rheumatology Physician and practices in Portland, Oregon. Credentials: M.D..
How much does Esther Hwang, M.D. prescribe under Medicare Part D? ▼
In 2023, Esther Hwang, M.D. wrote 1,506 Medicare Part D claims totaling $1.2M in drug costs for 279 beneficiaries.
Where is Esther Hwang, M.D. located? ▼
Esther Hwang, M.D. is located at 3550 N INTERSTATE AVE, Portland, OR, 97227. Phone: (800) 813-2000.
What is Esther Hwang, M.D.'s NPI number? ▼
Esther Hwang, M.D.'s National Provider Identifier (NPI) is 1215035670, issued on 09/20/2006.
How many Rheumatology Physician providers are there in the US? ▼
There are 6,181 Rheumatology Physician providers across 52 states in the US. The average Rheumatology Physician provider writes 2,054 Medicare Part D claims per year.
What drugs does Esther Hwang, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Esther Hwang, M.D.'s most frequently prescribed drugs include Methotrexate, Prednisone, Hydroxychloroquine Sulfate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Esther Hwang, M.D. accept Medicare? ▼
Esther Hwang, M.D. appears in CMS Medicare data with 1,506 Part D claims and 279 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Esther Hwang, M.D.'s credentials? ▼
Esther Hwang, M.D.'s NPI is 1215035670 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.