Mark F. Berntsen, MD
Internal Medicine Physician · Greeley, CO
Mark F. Berntsen, MD is an internal medicine physician with a practice address in Greeley, Colorado, and NPI 1730166687, issued on Dec 30, 2005. Check the license (Colorado 35897, as entered in NPPES) on the Colorado Medical Board; the Medicare figures below come from public CMS files.
- Name
- Mark F. Berntsen
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 35897 CO
Self-reported in NPPES; status is on the state search - Practice location
- 1900 16TH St, Greeley, CO 80631
- Phone
- (970) 350-2438
- Enumerated
- Dec 30, 2005
- Record last updated
- Jul 1, 2013 (not updated in 13 years: call before relying on the address or phone)
- Fax
- (970) 350-2473
- Medicaid ID
- 01358977 CO
- Medicare enrollment
- Enrolled (PECOS I20090902000324); accepts Medicare assignment
- Medical or professional school
- University Of Kansas School Of Med (Kc/Wich/Sal), 1993
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,046 in Colorado → Look up another NPI →
Also registered at 1900 16TH St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Tyler Abbey, DOInternal Medicine Physician1730572694
- Leandra Bazan, PA-C, MTPhysician Assistant1407947286
- Robert Cash, MDInternal Medicine Physician1285611152
- John Charbonneau, MDOccupational Medicine Physician1942272752
- Janell Durnen, MSN, APN, FNP-BCFamily Nurse Practitioner1265874929
- John Ebens, MDInternal Medicine Physician1649257544
Verify Mark F. Berntsen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersColorado Medical Board
Search for license 35897Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
8.1 times the Medicare Part D claims of the average internal medicine physician in 2024
25,805 Medicare Part D claims for 1,711 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 723 claims were for opioids.
Most prescribed
- Levothyroxine Sodium1,362 claims
- Amlodipine Besylate1,252 claims
- Atorvastatin Calcium1,221 claims
- Lisinopril1,107 claims
- Losartan Potassium1,089 claims
- Omeprazole744 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
- Poudre Valley Medical Group LLCGreeley, CO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark F. Berntsen among 2,046 internal medicine physician records in Colorado
Mark F. Berntsen, MD is one of 2,046 internal medicine physician records with a practice address in Colorado. 71% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 90% newer
- In a Medicare fileYes · 71% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated1993 · median 2006 among the 1,090 with a school on file
- Record last updated2013 · 61% 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 Colorado practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
37 internal medicine physician records list a practice address in Greeley
They are 37 of the 3,518 NPPES records with a practice address in Greeley, and 2,046 internal medicine physician records in Colorado.
All 2,046 in Colorado → Every provider in Greeley → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Julia BruceGreeley, CO 806311639136385
- Robert Cash, MDGreeley, CO 806311285611152
- Tesfaye Demeke, MDGreeley, CO 806311255352217
- Danielle Doro, M.D.Greeley, CO 806311437145190
- John Ebens, MDGreeley, CO 806311649257544
- Barbara Emerson, M.D.Greeley, CO 806311164573291
- Steven Kalt, MDGreeley, CO 806311225011554
- Steven Loecke, MDGreeley, CO 806311265410005
Common questions
What is Mark F. Berntsen, MD's NPI number?
Mark F. Berntsen, MD's National Provider Identifier (NPI) is 1730166687, issued on Dec 30, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Mark F. Berntsen, MD located?
The NPPES record lists a practice address at 1900 16TH St, Greeley, CO, 80631. Phone: (970) 350-2438. Providers update this record themselves, so call before visiting.
How can I verify Mark F. Berntsen, MD's license?
NPPES lists Colorado license number 35897, as entered by the provider. Search the Colorado Medical Board at https://dpo.colorado.gov/Medical. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Mark F. Berntsen, MD prescribe under Medicare Part D?
In 2024, Mark F. Berntsen, MD had 25,805 Medicare Part D claims for 1,711 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.