Jennifer L. Leoniak, DO

Medicare activity in 2024

Official CMS public-use data for Jennifer L. Leoniak, 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. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)1,729 services
2. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)513 services
3. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)174 services
4. Critical care, first 30-74 minutes (99291)103 services
5. Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)14 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 blood pressure75%
• High cholesterol75%
• Diabetes63%
• Chronic kidney disease54%
• Heart failure51%
• Ischemic heart disease48%

Hospitals where Jennifer L. Leoniak works

Medicare's Facility Affiliation Data lists Jennifer L. Leoniak 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.

• Doctors Medical CenterModesto, CA · Acute Care Hospital · Medicare rating: 1 of 5 stars · Emergency services: listed by Medicare · CCN 050464
• Emanuel Medical CenterTurlock, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050179
• Memorial Medical CenterModesto, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050557
• Mercy Medical CenterMerced, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050444

Practice locations

Addresses where Jennifer L. Leoniak is enrolled with Medicare (CMS data updated October 2, 2026).

• 1524 McHenry Ave, Suite 300Modesto, CA 95350 (209) 722‑4842
• 825 Delbon AveTurlock, CA 95382 (209) 656‑0183

Group practices

Medicare enrollment lists Jennifer L. Leoniak as a member of this group (CMS data updated October 2, 2026).

• Golden Valley Health Centers113 clinicians in the group

Specialties

• Internal Medicineprimary

Find other Internal Medicine doctors in California →

Other internal medicine doctors in Modesto

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

• Swapna Kamireddy, MD
• Yan Li, MD
• Abraham I. Montano, MD
• Howard G. Young, MD
• Bhagya Laxmi Gaddam, MD
• Wajdi N. Bader, MD
• Youhana Jacobs, MD
• Berhanu C. Tesfaye, MD

All internal medicine doctors in Modesto →

Other clinicians in Golden Valley Health Centers

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

• Christine Battaglia, DO
• Andrea Silva, MD
• Nichole D. Liggins, MD
• Regina M. Butler, NP
• Susan F. Kraus, MD
• Eseosa Edo Osagie, 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