NPI registry status
Active
2026 NPPES data Obstetrics & Gynecology Physician NPI 1528029345 M.D.
Verify on CMS → Alvin Nakamura, M.D.
Obstetrics & Gynecology 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 44,326 in Obstetrics & Gynecology 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
170
Medicare Part D claims · 48 beneficiaries · Obstetrics & Gynecology Physician avg: 179
Generic prescribing
91%
generic claims · 9% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Alvin Nakamura, M.D. filed 170 Medicare Part D claims in 2023 as an Obstetrics & Gynecology Physician in Portland, Oregon, prescribing 91% generic.
- 170
- Part D claims, 2023
- 91%
- generic prescribing
- ≥35th
- 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 1528029345 · Obstetrics & Gynecology Physician
NPI-10 · ENUM-LEGACY · TAX-MID · RX-LIGHT · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1528029345
- ENUM-LEGACY 2006
- TAX-MID 44K Obstetrics &
- RX-LIGHT 170
- BOOK-LIGHT 663 in Oregon
- PHOTO-ENUM Terry Downing · 2006
Alvin Nakamura, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
170 ≥ 35th percentile 35% 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)
Alvin Nakamura, M.D. 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 Alvin Nakamura, M.D.?
Quality data not reportedPrimary specialty
Obstetrics & Gynecology Physician
Medicare Part D claims
170 5% vs specialty avg
Specialty distribution in Oregon
How Obstetrics & Gynecology 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 Obstetrics & Gynecology 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 | 1528029345 |
|---|---|
| Specialty | Obstetrics & Gynecology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 03/31/2006 |
Brand vs generic prescribing mix · Generic-heavy
Alvin Nakamura, M.D. - brand share 9.0%
Obstetrics & Gynecology Physician average
9% brand-name claims vs 91% generic, on 170 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.
170
Total Claims
$14K
Total Drug Cost
48
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 362
- Total Day Supply
- 10,150
- Brand vs Generic
- 9% brand / 91% generic
- Brand Drug Cost
- $6K
- Generic Drug Cost
- $8K
Patient Demographics
- Average Patient Age
- 68.8 years
- Avg HCC Risk Score
- 0.77
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Alvin Nakamura, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Estradiol
Estradiol
68 claims
- Larin 15
Larin
15 claims
- Dotti 14
Dotti
14 claims
| Drug | Claims |
|---|---|
| Estradiol | 68 |
| Larin Norethindrone Ac-Eth Estradiol | 15 |
| Dotti Estradiol | 14 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Obstetrics & Gynecology Physician Overview
How Alvin Nakamura, M.D. fits within the Obstetrics & Gynecology Physician landscape nationally.
44,326
Obstetrics & Gynecology Physician Providers in US
56
States with Obstetrics & Gynecology Physician
179
Avg Claims per Provider
Alvin Nakamura, M.D.'s 170 claims are below the specialty average of 179.
Nationwide Obstetrics & Gynecology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Nakamura, both outside Oregon so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Obstetrics & Gynecology Physician Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Nakamura.
One of 663 Obstetrics & Gynecology Physician providers enrolled in Oregon, 5 are shown here.
Dr. Chidimma Abanulo
M.D.
Hillsboro, OR
Dr. Heather Abe
DO
Beaverton, OR
Dr. Diana Ackerman
M.D.
Bend, OR
Dr. Kerrie Adams
M.D.
Tualatin, OR
Dr. Samantha Adkins
MD
Milwaukie, OR
Compare Obstetrics & Gynecology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Alvin Nakamura, M.D.'s specialty? ▼
Alvin Nakamura, M.D. specializes in Obstetrics & Gynecology Physician and practices in Portland, Oregon. Credentials: M.D..
How much does Alvin Nakamura, M.D. prescribe under Medicare Part D? ▼
In 2023, Alvin Nakamura, M.D. wrote 170 Medicare Part D claims totaling $14K in drug costs for 48 beneficiaries.
Where is Alvin Nakamura, M.D. located? ▼
Alvin Nakamura, M.D. is located at 10000 SE MAIN ST, Portland, OR, 97216. Phone: (503) 257-7757.
What is Alvin Nakamura, M.D.'s NPI number? ▼
Alvin Nakamura, M.D.'s National Provider Identifier (NPI) is 1528029345, issued on 03/31/2006.
Does Alvin Nakamura, M.D. prescribe more brand-name or generic drugs? ▼
Alvin Nakamura, M.D.'s prescribing is 9% brand-name and 91% generic drugs by claim count, with $6K in brand drug costs.
How many Obstetrics & Gynecology Physician providers are there in the US? ▼
There are 44,326 Obstetrics & Gynecology Physician providers across 56 states in the US. The average Obstetrics & Gynecology Physician provider writes 179 Medicare Part D claims per year.
What drugs does Alvin Nakamura, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Alvin Nakamura, M.D.'s most frequently prescribed drugs include Estradiol, Larin, Dotti. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Alvin Nakamura, M.D. accept Medicare? ▼
Alvin Nakamura, M.D. appears in CMS Medicare data with 170 Part D claims and 48 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Alvin Nakamura, M.D.'s credentials? ▼
Alvin Nakamura, M.D.'s NPI is 1528029345 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
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.