Mark R. Hollemon, D.O.
Internal Medicine Physician · Portland, OR
Mark R. Hollemon, D.O. is an internal medicine physician with a practice address in Portland, Oregon, and NPI 1881709210, issued on Aug 19, 2006. Check the license (Oregon DO18822, as entered in NPPES) on the Oregon Medical Board; the Medicare figures below come from public CMS files.
- Name
- Mark R. Hollemon
- Credential
- D.O.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- DO18822 OR
Self-reported in NPPES; status is on the state search - Practice location
- 2330 NW Flanders St, Portland, OR 97210
- Phone
- (503) 224-0817
- Enumerated
- Aug 19, 2006
- Record last updated
- Feb 11, 2022
- Fax
- (503) 224-0839
- Medicare enrollment
- Enrolled (PECOS I20160627002444); accepts Medicare assignment
- Medical or professional school
- University Of North Texas Hsc, College Of Osteopathic Med, 1993
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,116 in Oregon → Look up another NPI →
Also registered at 2330 NW Flanders St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Mark R. Hollemon in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersOregon Medical Board
Search for license DO18822Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
80% fewer Medicare Part D claims than the average internal medicine physician in 2024
637 Medicare Part D claims for 217 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 13 claims were for opioids.
Most prescribed
- Atorvastatin Calcium36 claims
- Furosemide36 claims
- Amlodipine Besylate27 claims
- Clopidogrel19 claims
- Carvedilol17 claims
- Cephalexin17 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
- Permanente Medical Group IncSan Jose, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark R. Hollemon among 2,116 internal medicine physician records in Oregon
Mark R. Hollemon, 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 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 54% newer
- In a Medicare fileYes · 73% of these records are
- In the CMS Doctors and Clinicians fileYes · 58% of these records are
- Graduated1993 · median 2008 among the 1,232 with a school on file
- Record last updated2022 · 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
- Stephen Baugh, MDPortland, OR 972101972577740
- James Borden, MDPortland, OR 972101679555742
- Patrick Dunn, M.D.Portland, OR 972101669447231
- Barry Egener, MDPortland, OR 972101437124088
- Joyce KaynardPortland, OR 972101720053317
- Curtis Marr, M.D.Portland, OR 972101669447264
- Erich Meihoff, MDPortland, OR 972101144295916
- John Oppenheimer, MDPortland, OR 972101922071513
Common questions
What is Mark R. Hollemon, D.O.'s NPI number?
Mark R. Hollemon, D.O.'s National Provider Identifier (NPI) is 1881709210, issued on Aug 19, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark R. Hollemon, D.O. located?
The NPPES record lists a practice address at 2330 NW Flanders St, Portland, OR, 97210. Phone: (503) 224-0817. Providers update this record themselves, so call before visiting.
How can I verify Mark R. Hollemon, D.O.'s license?
NPPES lists Oregon license number DO18822, 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 Mark R. Hollemon, D.O. prescribe under Medicare Part D?
In 2024, Mark R. Hollemon, D.O. had 637 Medicare Part D claims for 217 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.