NPI registry status
Active
2026 NPPES data Gastroenterology Physician NPI 1619973351 DO
Verify on CMS → Diane Williams, DO
Gastroenterology 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 16,567 in Gastroenterology 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
728
Medicare Part D claims · 293 beneficiaries · Gastroenterology Physician avg: 833
Generic prescribing
80%
generic claims · 20% 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
Diane Williams, DO filed 728 Medicare Part D claims in 2023 as a Gastroenterology Physician in Portland, Oregon, prescribing 80% generic.
- 728
- Part D claims, 2023
- 80%
- 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.
Diane Williams, DO's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
728 Top 29% higher than 71% 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-eligible specialty (heuristic, not verified)
Diane Williams, DO 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 Diane Williams, DO?
Quality data not reportedPrimary specialty
Gastroenterology Physician
Medicare Part D claims
728 13% vs specialty avg
Specialty distribution in Oregon
How Gastroenterology 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 Gastroenterology 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 Williams, DO appears in the CMS NPPES registry as a Gastroenterology Physician provider holding DO credentials at 9701 SW BARNES RD, Portland, OR, 97225, with a listed phone of (503) 297-8081. NPI 1619973351 was issued on 06/27/2005.
Medicare Part D records for calendar year 2023 show 728 prescription claims written by this provider, covering 293 Medicare beneficiaries and totaling roughly $112K in drug spend, split 20% brand-name and 80% generic by claim count.
Gastroenterology Physician is a mid-sized specialty nationwide, with 16,567 enrolled providers across 54 states and an average of 833 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 | 1619973351 |
|---|---|
| Specialty | Gastroenterology Physician |
| Credentials | DO |
| Gender | Female |
| NPI Issued | 06/27/2005 |
Brand vs generic prescribing mix · Typical
Diane Williams, DO - brand share 20.0%
Gastroenterology Physician average
20% brand-name claims vs 80% generic, on 728 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.
728
Total Claims
$112K
Total Drug Cost
293
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,179
- Total Day Supply
- 29,386
- Brand vs Generic
- 20% brand / 80% generic
- Brand Drug Cost
- $81K
- Generic Drug Cost
- $31K
Patient Demographics
- Average Patient Age
- 72.0 years
- Avg HCC Risk Score
- 0.91
- Gender Split
- 81% female / 19% male
- Age Distribution
- <65: 21, 65-74: 167, 75-84: 94, 85+: 11
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Diane Williams, DO prescribes most
Top Medicare Part D drugs by claim count, 2023
- Pantoprazole Sodium
Pantoprazole Sodium
151 claims
- Famotidine
Famotidine
93 claims
- Omeprazole
Omeprazole
74 claims
- Sutab 57
Sutab
57 claims
- Dicyclomine Hcl 38
Dicyclomine Hcl
38 claims
- Ondansetron Odt 36
Ondansetron Odt
36 claims
- Budesonide Dr 30
Budesonide Dr
30 claims
- Ursodiol 21
Ursodiol
21 claims
| Drug | Claims |
|---|---|
| Pantoprazole Sodium | 151 |
| Famotidine | 93 |
| Omeprazole | 74 |
| Sutab Sod Sulf/Pot Chloride/Mag Sulf | 57 |
| Dicyclomine Hcl | 38 |
| Ondansetron Odt Ondansetron | 36 |
| Budesonide Dr Budesonide | 30 |
| Ursodiol | 21 |
| Ondansetron Hcl | 17 |
| Creon Lipase/Protease/Amylase | 13 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gastroenterology Physician Overview
How Diane Williams, DO fits within the Gastroenterology Physician landscape nationally.
16,567
Gastroenterology Physician Providers in US
54
States with Gastroenterology Physician
833
Avg Claims per Provider
Diane Williams, DO's 728 claims are below the specialty average of 833.
Nearby Gastroenterology Physician Providers in Oregon
Other clinicians with the same primary specialty enrolled in Oregon, drawn from the same CMS NPPES roster as Williams.
Dr. Peter Adesman
MD
Medford, OR
Dr. Kamran Aghaie
MD
Clackamas, OR
Dr. Joseph Ahn
M.D.
Portland, OR
Dr. Jeffrey Albaugh
MD
Portland, OR
Dr. Deron Amador
M.D.
Portland, OR
Compare Gastroenterology 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 Gastroenterology 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 Williams, DO's specialty? ▼
Diane Williams, DO specializes in Gastroenterology Physician and practices in Portland, Oregon. Credentials: DO.
How much does Diane Williams, DO prescribe under Medicare Part D? ▼
In 2023, Diane Williams, DO wrote 728 Medicare Part D claims totaling $112K in drug costs for 293 beneficiaries.
Where is Diane Williams, DO located? ▼
Diane Williams, DO is located at 9701 SW BARNES RD, Portland, OR, 97225. Phone: (503) 297-8081.
What is Diane Williams, DO's NPI number? ▼
Diane Williams, DO's National Provider Identifier (NPI) is 1619973351, issued on 06/27/2005.
Does Diane Williams, DO prescribe more brand-name or generic drugs? ▼
Diane Williams, DO's prescribing is 20% brand-name and 80% generic drugs by claim count, with $81K in brand drug costs.
How many Gastroenterology Physician providers are there in the US? ▼
There are 16,567 Gastroenterology Physician providers across 54 states in the US. The average Gastroenterology Physician provider writes 833 Medicare Part D claims per year.
What drugs does Diane Williams, DO prescribe most often? ▼
Based on 2023 Medicare Part D data, Diane Williams, DO's most frequently prescribed drugs include Pantoprazole Sodium, Famotidine, Omeprazole. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Diane Williams, DO accept Medicare? ▼
Diane Williams, DO appears in CMS Medicare data with 728 Part D claims and 293 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Diane Williams, DO's credentials? ▼
Diane Williams, DO's NPI is 1619973351 with credentials DO. 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.