Melissa N. Loja, MD

Medicare activity in 2024

Official CMS public-use data for Melissa N. Loja, 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. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)280 services
2. Ultrasound study of arm and leg arteries (93922)184 services
3. Ultrasound of both sides of head and neck blood flow (93880)181 services
4. Telephone medical discussion with physician, 5-10 minutes (99441)153 services
5. New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)115 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%
• Diabetes56%
• Chronic kidney disease54%
• Ischemic heart disease49%
• Arthritis44%

Hospitals where Melissa N. Loja works

Medicare's Facility Affiliation Data lists Melissa N. Loja 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.

• NorthBay Medical CenterFairfield, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050367
• Providence Queen of the Valley Medical CenterNapa, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050009

Practice locations

Addresses where Melissa N. Loja is enrolled with Medicare (CMS data updated October 2, 2026).

• 1000 Trancas StNapa, CA 94558 (707) 252‑4411
• 1020 Nut Tree Rd, Suite 290Vacaville, CA 95687 (707) 624‑8230
• 1860 Pennsylvania Ave, Suite 200Fairfield, CA 94533 (707) 646‑4180
• 3250 Beard RdNapa, CA 94558 (707) 646‑4180
• 4520 Business Ctr Dr, Suite 200Vacaville, CA 94534 (707) 646‑5500

Group practices

Medicare enrollment lists Melissa N. Loja as a member of these groups (CMS data updated October 2, 2026).

• Providence Medical Foundation1,466 clinicians in the group
• NorthBay Physicians Surgery Center, LLC324 clinicians in the group
• NorthBay Health Medical Foundation213 clinicians in the group

Specialties

• Vascular Surgeryprimary

Find other Vascular Surgery doctors in California →

Other vascular surgeons in California

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

• Andrew Nimmich, MD
• Jung J. Lim, DO
• Philip J. Hinton, MD
• Quang T. Vo, MD
• Hao D. Bui, MD
• Kian Mostafavi, MD
• Gautam Anand, MD
• Kelley D. Hodgkiss-Harlow, MD

All vascular surgeons in California →

Other clinicians in Providence Medical Foundation

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

• Lisa E. Morales, NP
• Hannah A. Knox, MD
• Donald L. Whisler, MD
• Eric S. Schmidt, MD
• Eugene J. Yoon, MD
• Quantin Pham, PA

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