Dena Witthaus, D.O.
Internal Medicine Physician · Portland, OR
Dena Witthaus, D.O. is an internal medicine physician with a practice address in Portland, Oregon, and NPI 1528354966, issued on Jun 23, 2011. Check the license (Oregon DO166704, as entered in NPPES) on the Oregon Medical Board; the Medicare figures below come from public CMS files.
- Name
- Dena Witthaus
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- DO166704 OR
PG154631 OR
Self-reported in NPPES; status is on the state search - Practice location
- 19500 SE Stark St, Portland, OR 97233
- Phone
- (800) 813-2000
- Enumerated
- Jun 23, 2011
- Record last updated
- Aug 27, 2025
- Medicare enrollment
- Enrolled (PECOS I20241014001464); accepts Medicare assignment
- Medical or professional school
- Arizona College Of Osteopathic Medicine Mid Western University, 2011
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,116 in Oregon → Look up another NPI →
Also registered at 19500 SE Stark St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Merrill Ahrens, MDInternal Medicine Physician1194839225
- Christopher Alaka, RPH, C.C.R.APharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1083982706
- Nicolle AsencioFamily Nurse Practitioner1225753692
- Richard Babal, MANAGEROptician1295824282
- Thomas Beaver, M.D.Internal Medicine Physician1215019112
- Jennifer Bishop, MDInternal Medicine Physician1548284557
Verify Dena Witthaus in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersOregon Medical Board
Search for license DO166704Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.2 times the Medicare Part D claims of the average internal medicine physician in 2024
7,035 Medicare Part D claims for 1,146 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 672 claims were for opioids.
Most prescribed
- Atorvastatin Calcium333 claims
- Lisinopril254 claims
- Hydrocodone-Acetaminophen248 claims
- Oxycodone Hcl227 claims
- Losartan Potassium225 claims
- Levothyroxine Sodium219 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Kaiser Foundation Health Plan OF The NorthwestVancouver, WA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Dena Witthaus among 2,116 internal medicine physician records in Oregon
Dena Witthaus, D.O. is one of 2,116 internal medicine physician records with a practice address in Oregon. 73% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2011, is newer than 65% of them.
- NPI issued2011 · 65% of these records are older, 32% newer
- In a Medicare fileYes · 73% of these records are
- In the CMS Doctors and Clinicians fileYes · 58% of these records are
- Graduated2011 · median 2008 among the 1,232 with a school on file
- Record last updated2025 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Oregon practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
889 internal medicine physician records list a practice address in Portland
They are 889 of the 42,088 NPPES records with a practice address in Portland, and 2,116 internal medicine physician records in Oregon.
All 2,116 in Oregon → Every provider in Portland → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Merrill Ahrens, MDPortland, OR 972331194839225
- Thomas Beaver, M.D.Portland, OR 972331215019112
- Jennifer Bishop, MDPortland, OR 972331548284557
- Benjamin Brody, M.D.Portland, OR 972331245243799
- Brian Gould, M.D.Portland, OR 972331073535266
- Glenn Greeder, MDPortland, OR 972331821184250
- June GreenePortland, OR 972331932284346
- Max Grishkevich, MDPortland, OR 972331477518637
Common questions
What is Dena Witthaus, D.O.'s NPI number?
Dena Witthaus, D.O.'s National Provider Identifier (NPI) is 1528354966, issued on Jun 23, 2011. An NPI identifies a provider in billing; it is not a license.
Where is Dena Witthaus, D.O. located?
The NPPES record lists a practice address at 19500 SE Stark St, Portland, OR, 97233. Phone: (800) 813-2000. Providers update this record themselves, so call before visiting.
How can I verify Dena Witthaus, D.O.'s license?
NPPES lists Oregon license number DO166704, as entered by the provider. Search the Oregon Medical Board at https://www.oregon.gov/OMB/Pages/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Dena Witthaus, D.O. prescribe under Medicare Part D?
In 2024, Dena Witthaus, D.O. had 7,035 Medicare Part D claims for 1,146 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.