Jennifer S. Siani, MD

Medicare activity in 2024

Official CMS public-use data for Jennifer S. Siani, 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. Injection, romosozumab-aqqg, 1 mg (J3111)12,810 services
2. Injection, denosumab, 1 mg (J0897)2,160 services
3. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)518 services
4. New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)174 services
5. Hemoglobin a1c level (83036)143 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).

• High cholesterol75%
• High blood pressure68%
• Arthritis55%
• Diabetes41%
• Osteoporosis41%
• Ischemic heart disease29%

Hospitals where Jennifer S. Siani works

Medicare's Facility Affiliation Data lists Jennifer S. Siani 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.

• Adventist Health Simi ValleySimi Valley, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050236
• Ronald Reagan UCLA Medical CenterLos Angeles, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050262

Practice locations

Addresses where Jennifer S. Siani is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 8; the Medicare profile lists all.

• 100 Moody Ct, Suite 200Thousand Oaks, CA 91360 (805) 418‑3500
• 1250 La Venta Dr, Suite 207Westlake Village, CA 91361 (805) 494‑6920
• 15503 Ventura BlvdEncino, CA 91436 (818) 461‑8148
• 19950 Rinaldi StPorter Ranch, CA 91326
• 2020 Santa Monica Blvd, Suite 210Santa Monica, CA 90404 (310) 458‑2381

Group practices

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

• The Regents of the University of California1,462 clinicians in the group
• Venice Family Clinic102 clinicians in the group

Specialties

• Endocrinologyprimary
• Internal Medicinealso

Find other Endocrinology doctors in California →

Other endocrinologists in Thousand Oaks

Clinicians with the same Medicare primary specialty in Thousand Oaks, CA — not a recommendation.

• Harris L. Wasser, MD
• Maryam Sharifi, MD
• Allison T. Yip, MD
• Jeffrey Wei, MD
• Deepashree Gupta

All endocrinologists in Thousand Oaks →

Other clinicians in The Regents of the University of California

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

• Vanessa R. Holland, MD
• Bryan A. Medina, MD
• Manan P. Shah, MD
• Sravani Penumarty, MD
• Shailesh A. Balasubramanian, MD
• Mark B. Benor, 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