Karen B. Alderfer, MD
Diagnostic Radiology Physician · Fort Collins, CO
Karen B. Alderfer, MD is a diagnostic radiology physician with a practice address in Fort Collins, Colorado, and NPI 1043534654, issued on Mar 25, 2010. Check the license (Colorado CDR.0001517, as entered in NPPES) on the Colorado Medical Board; the Medicare figures below come from public CMS files.
- Name
- Karen B. Alderfer
- Credential
- MD
- Primary taxonomy
- Diagnostic Radiology Physician 2085R0202X
- License numbers
- CDR.0001517 CO
16586 NV
A121137 CA
34356 NE
14311C WY
Self-reported in NPPES; status is on the state search - Practice location
- 1024 S Lemay Ave, Fort Collins, CO 80524
- Phone
- (970) 484-4757
- Enumerated
- Mar 25, 2010
- Record last updated
- Jul 1, 2025
- Fax
- (970) 484-4759
- Medicare enrollment
- Enrolled (PECOS I20160823001505); accepts Medicare assignment
- Medical or professional school
- University Of Nevada School Of Medicine, 2010
- Entity
- Type 1 · individual
8 nearest diagnostic radiology physician records → All 796 in Colorado → Look up another NPI →
Also registered at 1024 S Lemay Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Guy Alexander, MDDiagnostic Radiology Physician1083989362
- Michael ApostleEmergency Medicine Physician1952326407
- Carlos ArguellesEmergency Medicine Physician1417962960
- Everett AustinEmergency Medicine Physician1548503758
- Alvis Ayaba-Apawu, M.A., PHD. LPC.LAC.Professional Counselor1154553691
- Bree Bacalis, NPNurse Practitioner1659861359
Verify Karen B. Alderfer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersColorado Medical Board
Search for license CDR.0001517Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
The practice group's MIPS final score for 2023 (Medicare payment program): 84.4 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through 2 group practices
- Fort Collins Radiologic Associates PCLas Vegas, NV
- Uchealth Imaging Services LLCDenver, CO
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Karen B. Alderfer among 796 diagnostic radiology physician records in Colorado
Karen B. Alderfer, MD is one of 796 diagnostic radiology physician records with a practice address in Colorado. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 69% of them.
- NPI issued2010 · 69% of these records are older, 29% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 71% of these records are
- Graduated2010 · median 2006 among the 562 with a school on file
- Record last updated2025 · 47% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0202X and a Colorado practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Diagnostic Radiology Physician providers in Colorado
There are 796 diagnostic radiology physician records in Colorado.
All 796 in Colorado → Every provider in Fort Collins → Diagnostic Radiology Physician nationwide →
The 8 diagnostic radiology physician records with the nearest ZIP codes
- Bruce Berkowitz, MDFort Collins, CO 805241467477109
- Timothy Duncan, MDFort Collins, CO 805241982674628
- Deborah Gunderson, MDFort Collins, CO 805241285659920
- Paul Johnson, M.D.Fort Collins, CO 805241720053036
- Bob Klingelheber, DOFort Collins, CO 805241528083276
- Lisa Langmo, M.D.Fort Collins, CO 805241508863549
- Andrea Lyons, M.D.Fort Collins, CO 805241417922188
- Joseph Mack, M.D.Fort Collins, CO 805241467439745
Common questions
What is Karen B. Alderfer, MD's NPI number?
Karen B. Alderfer, MD's National Provider Identifier (NPI) is 1043534654, issued on Mar 25, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Karen B. Alderfer, MD located?
The NPPES record lists a practice address at 1024 S Lemay Ave, Fort Collins, CO, 80524. Phone: (970) 484-4757. Providers update this record themselves, so call before visiting.
How can I verify Karen B. Alderfer, MD's license?
NPPES lists Colorado license number CDR.0001517, 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.
What is Karen B. Alderfer, MD's MIPS final score?
The 2023 MIPS final score is 84.4 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.