NPI registry status
Active
2026 NPPES data Family Medicine Physician NPI 1023336526 MD
Verify on CMS → Diana Feldstein, MD
Family Medicine 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 147,760 in Family Medicine 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
387
Medicare Part D claims · 59 beneficiaries · Family Medicine Physician avg: 3K
What the federal data shows
Diana Feldstein, MD filed 387 Medicare Part D claims in 2023 as a Family Medicine Physician in Portland, Oregon.
- 387
- Part D claims, 2023
- ≥57th
- pct by Part D claim volume (lower-bound band)
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.
CMS NPPES provider registry desk
NPI 1023336526 · Family Medicine Physician
NPI-10 · ENUM-MID · TAX-MEGA · RX-LIGHT · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1023336526
- ENUM-MID 2010
- TAX-MEGA 148K Family Medicine
- RX-LIGHT 387
- BOOK-LIGHT 2,650 in Oregon
- PHOTO-ENUM Abby Housman · 2010
Diana Feldstein, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
387 ≥ 57th percentile 57% of 1,370,886 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2023
◑
Board-eligible specialty (heuristic, not verified)
Diana Feldstein, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Diana Feldstein, MD?
Quality data not reportedPrimary specialty
Family Medicine Physician
Medicare Part D claims
387 89% vs specialty avg
Specialty distribution in Oregon
How Family Medicine 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 Family Medicine 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).
Practice Address
Provider Details
| NPI | 1023336526 |
|---|---|
| Specialty | Family Medicine Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 05/07/2010 |
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
387
Total Claims
$138K
Total Drug Cost
59
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 421
- Total Day Supply
- 12,005
- Generic Drug Cost
- $13K
Patient Demographics
- Average Patient Age
- 78.1 years
- Avg HCC Risk Score
- 2.77
- Gender Split
- 69% female / 31% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Diana Feldstein, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Famotidine
Famotidine
27 claims
- Lisinopril
Lisinopril
17 claims
- Tamsulosin Hcl
Tamsulosin Hcl
17 claims
- Gabapentin
Gabapentin
16 claims
- Metoprolol Succinate
Metoprolol Succinate
14 claims
- Sertraline Hcl
Sertraline Hcl
14 claims
- Risperdal Consta
Risperdal Consta
12 claims
- Atorvastatin Calcium
Atorvastatin Calcium
11 claims
| Drug | Claims |
|---|---|
| Famotidine | 27 |
| Lisinopril | 17 |
| Tamsulosin Hcl | 17 |
| Gabapentin | 16 |
| Metoprolol Succinate | 14 |
| Sertraline Hcl | 14 |
| Risperdal Consta Risperidone Microspheres | 12 |
| Atorvastatin Calcium | 11 |
| Eliquis Apixaban | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Family Medicine Physician Overview
How Diana Feldstein, MD fits within the Family Medicine Physician landscape nationally.
147,760
Family Medicine Physician Providers in US
56
States with Family Medicine Physician
3,418
Avg Claims per Provider
Diana Feldstein, MD's 387 claims are below the specialty average of 3,418.
Nationwide Family Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Feldstein, both outside Oregon so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2010)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Family Medicine Physician Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Feldstein.
One of 2,650 Family Medicine Physician providers enrolled in Oregon, 5 are shown here.
Dr. Roxana Abbott
DO
Portland, OR
Dr. David Abdun-Nur
M.D.
Grants Pass, OR
Dr. Traci Ackron
D.O.
Hillsboro, OR
Dr. Orlando Acosta
MD
Hood River, OR
Dr. Michele Adamcak
D.O.
Tigard, OR
Compare Family Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Diana Feldstein, MD's specialty? ▼
Diana Feldstein, MD specializes in Family Medicine Physician and practices in Portland, Oregon. Credentials: MD.
How much does Diana Feldstein, MD prescribe under Medicare Part D? ▼
In 2023, Diana Feldstein, MD wrote 387 Medicare Part D claims totaling $138K in drug costs for 59 beneficiaries.
Where is Diana Feldstein, MD located? ▼
Diana Feldstein, MD is located at 4900 NE GLISAN ST, Portland, OR, 97213. Phone: (503) 215-0750.
What is Diana Feldstein, MD's NPI number? ▼
Diana Feldstein, MD's National Provider Identifier (NPI) is 1023336526, issued on 05/07/2010.
How many Family Medicine Physician providers are there in the US? ▼
There are 147,760 Family Medicine Physician providers across 56 states in the US. The average Family Medicine Physician provider writes 3,418 Medicare Part D claims per year.
What drugs does Diana Feldstein, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Diana Feldstein, MD's most frequently prescribed drugs include Famotidine, Lisinopril, Tamsulosin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Diana Feldstein, MD accept Medicare? ▼
Diana Feldstein, MD appears in CMS Medicare data with 387 Part D claims and 59 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Diana Feldstein, MD's credentials? ▼
Diana Feldstein, MD's NPI is 1023336526 with credentials MD. 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
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.