Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Dr. John Denker, MD

Individual provider Adult Medicine Physician · NPI 1942201546

Dr. John Denker, MD is registered under General Practice in Portland, Oregon. Graduated from Oregon Health Sciences University School of Medicine in 1980, 46 years ago. Practices with Marquis Clinical Services LLC, a 24-clinician group and accepts Medicare assignment. Licensed in Oregon.

Years since qualifying
46
Trained at
Oregon Health Sciences University School of Medicine
Licensed in
OR
In the registry since
2005
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

5622 SE 41st Ave
Portland, OR 97202-7516 Not confirmed with CMS for 19 years — call before visiting
Phone: (503) 774-6929
Fax: (503) 774-6924
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Adult Medicine Physician (primary) Taxonomy 207QA0505X · Licence MD 12668 (OR)
Geriatric Medicine (Family Medicine) Physician Taxonomy 207QG0300X · Licence MD 12668 (OR)

Record details

NPI number1942201546
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedAugust 3, 2005
Last updated in NPPESOctober 16, 2007

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyGENERAL PRACTICE
Medical schoolOREGON HEALTH SCIENCES UNIVERSITY SCHOOL OF MEDICINE
Graduated 1980 (46 years in practice)
Group practice Marquis Clinical Services Llc — 24 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Removal of tissue 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients226
Services billed 365 a service is one billed item, such as a visit, a test or a procedure
Average patient age80

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Marquis Clinical Services LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 24 clinicians in the practice; 12 are shown here.

Other providers in Portland