NPPES file of Aug 9, 2026

Croix Fossum, M.D.

Radiation Oncology Physician · San Diego, CA

Croix Fossum, M.D. is a radiation oncology physician with a practice address in San Diego, California, and NPI 1104351006, issued on Apr 28, 2017. Check the license (California A159160, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1104351006
Name
Croix Fossum
Credential
M.D.
Primary taxonomy
Radiation Oncology Physician 2085R0001X
License number
A159160 CA
Self-reported in NPPES; status is on the state search
Practice location
7901 Frost St, San Diego, CA 92123
Phone
(858) 939-5010
Enumerated
Apr 28, 2017
Record last updated
Feb 18, 2026
Fax
(858) 939-5021
Medicare enrollment
Enrolled (PECOS I20220701002784); accepts Medicare assignment
Medical or professional school
Mayo Medical School, 2017
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest radiation oncology physician records → All 735 in California → Look up another NPI →

Also registered at 7901 Frost St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Aileen Afshar, MDInternal Medicine Physician1134689946
  2. Saad Alkhider, MDInternal Medicine Physician1447712062
  3. Mustafa Alwash, M.DHospitalist Physician1679936439
  4. Alexandra Anjier, MDEmergency Medicine Physician1467087510
  5. Anna Astashchanka, MDPulmonary Disease Physician1821594359
  6. Amir Bahreman, M.D.Internal Medicine Physician1124249388

Verify Croix Fossum in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A159160    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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13% fewer Medicare Part D claims than the average radiation oncology physician in 2024

116 Medicare Part D claims for 35 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D.

  1. Croix Fossum116
  2. Specialty average134

Most prescribed

  1. Gabapentin17 claims
  2. Lidocaine Hcl Viscous17 claims
  3. Tamsulosin Hcl17 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.

Industry payments in 2024: $672.12

20 payments; by number, the most common kind was food and beverage; the largest payer was icotec Medical Inc. The 3,275 providers of this specialty with any payment received $1,897.85 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Croix Fossum$672.12
  2. Specialty average$1,897.85

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through one group practice

  1. X-Ray Medical Group Radiation Oncology IncSan Diego, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Croix Fossum among 735 radiation oncology physician records in California

Croix Fossum, M.D. is one of 735 radiation oncology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 87% of them.

  • NPI issued2017 · 87% of these records are older, 11% newer
  • In a Medicare fileYes · 83% of these records are
  • In the CMS Doctors and Clinicians fileYes · 74% of these records are
  • Graduated2017 · median 2005 among the 545 with a school on file
  • Record last updated2026 · 55% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Radiation Oncology Physician providers in California

There are 735 radiation oncology physician records in California.

All 735 in California → Every provider in San Diego → Radiation Oncology Physician nationwide →

The 8 radiation oncology physician records with the nearest ZIP codes

  1. Lori Coleman, MDSan Diego, CA 921231053348920
  2. Siavash Jabbari, MDSan Diego, CA 921231720314107
  3. Geoffrey Weinstein, MDSan Diego, CA 921231841233947
  4. Andrew Chang, M.D.San Diego, CA 921211255513859
  5. Jehee Choi, MDSan Diego, CA 921211619260056
  6. Brian Chou, MDSan Diego, CA 921211770070609
  7. Iain Macewan, M.D.San Diego, CA 921211326300401
  8. Atmaram Pai Panandiker, MDSan Diego, CA 921211871552950

Common questions

What is Croix Fossum, M.D.'s NPI number?

Croix Fossum, M.D.'s National Provider Identifier (NPI) is 1104351006, issued on Apr 28, 2017. An NPI identifies a provider in billing; it is not a license.

Where is Croix Fossum, M.D. located?

The NPPES record lists a practice address at 7901 Frost St, San Diego, CA, 92123. Phone: (858) 939-5010. Providers update this record themselves, so call before visiting.

How can I verify Croix Fossum, M.D.'s license?

NPPES lists California license number A159160, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does Croix Fossum, M.D. prescribe under Medicare Part D?

In 2024, Croix Fossum, M.D. had 116 Medicare Part D claims for 35 beneficiaries; the average among radiation oncology physician prescribers was 134. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.