Jennifer De Los Santos, MD

Medicare activity in 2024

Official CMS public-use data for Jennifer De Los Santos, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Most frequent services

1. Ct guidance for insertion of radiation therapy fields (77014)423 services
2. Radiation treatment management, 5 treatment sessions (77427)113 services
3. Calculation of radiation therapy dose (77300)111 services
4. Stereoscopic x-ray guidance for localization of target volume for the delivery of radiation therapy (G6002)111 services
5. Design and construction of complex radiation treatment device (77334)71 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

• Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)73%
• High blood pressure70%
• High cholesterol69%
• Arthritis35%
• Anxiety28%
• Ischemic heart disease27%

Hospitals where Jennifer De Los Santos works

Medicare's Facility Affiliation Data lists Jennifer De Los Santos at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

• Alton Memorial HospitalAlton, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140002
• Barnes Jewish HospitalSaint Louis, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260032
• Barnes-Jewish St Peters HospitalSaint Peters, MO · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 260191
• Barnes-Jewish West County HospitalCreve Coeur, MO · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 260162
• Memorial HospitalBelleville, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140185

Practice locations

Addresses where Jennifer De Los Santos is enrolled with Medicare (CMS data updated October 2, 2026).

• 1 Memorial DrAlton, IL 62002
• 4500 Memorial DrBelleville, IL 62226
• 4921 Parkview Pl, Lowr LvlSaint Louis, MO 63110 (314) 362‑9715
• 5225 Mid America PlzSaint Louis, MO 63129 (314) 286‑1911
• 6 Memorial Dr, Bldg CAlton, IL 62002 (618) 433‑7979

Group practices

Medicare enrollment lists Jennifer De Los Santos as a member of these groups (CMS data updated October 2, 2026).

• Washington University3,029 clinicians in the group
• Washington University Physicians in Illinois Inc175 clinicians in the group

Specialties

• Radiation Oncologyprimary

Find other Radiation Oncology doctors in Illinois →

Other radiation oncologists in Illinois

Clinicians with the same Medicare primary specialty in Illinois — not a recommendation.

• Mustafaa S. Mahmood, MD
• Santosh V. Yajnik, MD
• Amit D. Bhate, MD
• Matthew Harkenrider, MD
• Andrew Cook, MD
• Jacob S. Witt, MD
• Ramji R. Rajendran, MD
• Kevin P. Lui, MD

All radiation oncologists in Illinois →

Other clinicians in Washington University

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

• Lulu Sun, MD
• Bryan A. Sisk, MD
• Sofia B. Ramos Bartolomei
• Salah G. Keyrouz, MD
• Jerold W. Wallis, MD
• Tara C. Copper, MD

Clinician information

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians