NPI registry status
Active
2026 NPPES data Specialist NPI 1538282447 MD
Verify on CMS → Diana Negreanu, MD
Specialist 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 69,608 in Specialist, 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
1K
Medicare Part D claims · 201 beneficiaries · Specialist avg: 1K
Generic prescribing
48%
generic claims · 46% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Diana Negreanu, MD filed 1,255 Medicare Part D claims in 2023 as a Specialist in Portland, Oregon, prescribing 48% generic.
- 1K
- Part D claims, 2023
- 48%
- generic prescribing
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.
Diana Negreanu, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,255 Top 22% higher than 78% 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
What does the federal data show about Diana Negreanu, MD?
Quality data not reportedPrimary specialty
Specialist
Medicare Part D claims
1,255 15% vs specialty avg
Specialty distribution in Oregon
How Specialist 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 Specialist. 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).
Diana Negreanu, MD appears in the CMS NPPES registry as a Specialist provider holding MD credentials at 5050 NE HOYT ST STE 317, Portland, OR, 97213, with a listed phone of (503) 256-4096. NPI 1538282447 was issued on 04/06/2007.
Medicare Part D records for calendar year 2023 show 1,255 prescription claims written by this provider, covering 201 Medicare beneficiaries and totaling roughly $397K in drug spend, split 46% brand-name and 48% generic by claim count.
Specialist is a high-volume specialty nationwide, with 69,608 enrolled providers across 55 states and an average of 1,474 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 | 1538282447 |
|---|---|
| Specialty | Specialist |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 04/06/2007 |
Hospital and facility affiliations
Facilities where Diana Negreanu, MD 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.
The Endocrine Clinic PC
Portland, OR
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Above average
Diana Negreanu, MD - brand share 46.0%
Specialist average
46% brand-name claims vs 48% generic, on 1,255 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,255
Total Claims
$397K
Total Drug Cost
201
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 3,056
- Total Day Supply
- 90,701
- Brand vs Generic
- 46% brand / 48% generic
- Brand Drug Cost
- $366K
- Generic Drug Cost
- $23K
Patient Demographics
- Average Patient Age
- 71.4 years
- Avg HCC Risk Score
- 1.19
- Gender Split
- 72% female / 28% 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 Negreanu, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Levothyroxine Sodium
Levothyroxine Sodium
185 claims
- Synthroid
Synthroid
122 claims
- Hydrocortisone 56
Hydrocortisone
56 claims
- Methimazole 53
Methimazole
53 claims
- Hydrochlorothiazide 46
Hydrochlorothiazide
46 claims
- Metformin Hcl 45
Metformin Hcl
45 claims
- Liothyronine Sodium 37
Liothyronine Sodium
37 claims
- Humalog Kwikpen U-… 34
Humalog Kwikpen U-100
34 claims
| Drug | Claims |
|---|---|
| Levothyroxine Sodium | 185 |
| Synthroid Levothyroxine Sodium | 122 |
| Hydrocortisone | 56 |
| Methimazole | 53 |
| Hydrochlorothiazide | 46 |
| Metformin Hcl | 45 |
| Liothyronine Sodium | 37 |
| Humalog Kwikpen U-100 Insulin Lispro | 34 |
| Alendronate Sodium | 31 |
| Testosterone Cypionate | 30 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Specialist Overview
How Diana Negreanu, MD fits within the Specialist landscape nationally.
69,608
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider
Diana Negreanu, MD's 1,255 claims are below the specialty average of 1,474.
Nearby Specialist Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Negreanu.
Taylor Abrigo
Portland, OR
Dr. Jeffrey Absalon
MD
Bend, OR
Dr. Christopher Adams
CRM
Albany, OR
Dr. Ross Adams
LMT
Ashland, OR
Dr. Daryl Adamson
MD
Portland, OR
Compare Specialist 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 Specialist 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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Medical Specialties Explained
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Frequently Asked Questions
What is Diana Negreanu, MD's specialty? ▼
Diana Negreanu, MD specializes in Specialist and practices in Portland, Oregon. Credentials: MD.
How much does Diana Negreanu, MD prescribe under Medicare Part D? ▼
In 2023, Diana Negreanu, MD wrote 1,255 Medicare Part D claims totaling $397K in drug costs for 201 beneficiaries.
Where is Diana Negreanu, MD located? ▼
Diana Negreanu, MD is located at 5050 NE HOYT ST STE 317, Portland, OR, 97213. Phone: (503) 256-4096.
What is Diana Negreanu, MD's NPI number? ▼
Diana Negreanu, MD's National Provider Identifier (NPI) is 1538282447, issued on 04/06/2007.
Does Diana Negreanu, MD prescribe more brand-name or generic drugs? ▼
Diana Negreanu, MD's prescribing is 46% brand-name and 48% generic drugs by claim count, with $366K in brand drug costs.
How many Specialist providers are there in the US? ▼
There are 69,608 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does Diana Negreanu, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Diana Negreanu, MD's most frequently prescribed drugs include Levothyroxine Sodium, Synthroid, Hydrocortisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Diana Negreanu, MD accept Medicare? ▼
Diana Negreanu, MD appears in CMS Medicare data with 1,255 Part D claims and 201 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Diana Negreanu, MD's credentials? ▼
Diana Negreanu, MD's NPI is 1538282447 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
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.