Nagui S. Achamallah, MD

Medicare activity in 2024

Official CMS public-use data for Nagui S. Achamallah, 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. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)64 services
2. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)35 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 cholesterol73%
• Anxiety71%
• Depression62%
• Alzheimer's disease or dementia61%
• Diabetes45%

Hospitals where Nagui S. Achamallah works

Medicare's Facility Affiliation Data lists Nagui S. Achamallah 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.

• John Muir Medical Center - Concord CampusConcord, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050496
• St Johns Regional Medical CenterOxnard, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050082

Practice locations

Addresses where Nagui S. Achamallah is enrolled with Medicare (CMS data updated October 2, 2026).

• 14850 Roscoe BlvdPanorama City, CA 91402 (818) 787‑2222
• 1601 Ygnacio Valley RdWalnut Creek, CA 94598 (925) 939‑3000
• 325 W Hospitality LnSan Bernardino, CA 92408 (866) 205‑3595
• 9961 Sierra AveFontana, CA 92335 (909) 427‑5000

Group practices

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

• Southern California Permanente Medical Group11,293 clinicians in the group
• Cep America - Psychiatry PC93 clinicians in the group
• Alliance for Wellness Inc56 clinicians in the group

Specialties

• Psychiatryprimary

Find other Psychiatry doctors in California →

Other psychiatrists in Panorama City

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

• Melissa E. Vallas, MD
• Teresa Nolfi, MD
• Mithun Medagangoda, DO
• Mark Laty, MD
• Anil Sharma, MD
• Clark Chen, DO
• Jason P. Lee, MD
• Marjorie E. Adler, MD

All psychiatrists in Panorama City →

Other clinicians in Southern California Permanente Medical Group

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

• Nancy A. Habib, MD
• Ken H. Uyesugi, OD
• Sherry Syed, MD
• Arthur H. Wong, MD
• Asma J. Saraj, MD
• Dahlia Tawfik-Sexton, 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