Quick answers
- Does David D. Nacionales accept Medicare assignment?
- Yes. Medicare's clinician data says David D. Nacionales accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does David D. Nacionales see?
- In 2024, CMS data shows 291 Original Medicare patients and 475 services for David D. Nacionales. This counts Original Medicare only and measures volume, not quality.
- What is David D. Nacionales's NPI number?
- 1699169227. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for David D. Nacionales, 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.
| Original Medicare patients | 291 |
|---|---|
| Services billed to Medicare | 475 |
| Different services or procedures | 28 |
| Participating Medicare provider | Yes |
| Average age of these patients | 71 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)83 services
- Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)61 services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)45 services
- Measurement of brain wave activity with video (veeg), 12-26 hours with review and report by health care professional (95720)37 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)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 cholesterol75%
- Diabetes58%
- Stroke or mini-stroke58%
- Arthritis46%
- Depression42%
Hospitals where David D. Nacionales works
Medicare's Facility Affiliation Data lists David D. Nacionales 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.
- Chino Valley Medical CenterChino, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050586
- Garden Grove Hospital & Medical CenterGarden Grove, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050230
- Montclair Hospital Medical CenterMontclair, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050758
- PIH Health Good Samaritan HospitalLos Angeles, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: not listed by Medicare · CCN 050471
- PIH Health Hospital-WhittierWhittier, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050169
Practice locations
Addresses where David D. Nacionales is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 7; the Medicare profile lists all.
- 11500 Brookshire AveDowney, CA 90241 (562) 904‑5000
- 1225 Wilshire BlvdLos Angeles, CA 90017 (213) 977‑2121
- 12401 Washington BlvdWhittier, CA 90602 (562) 698‑0811
- 12401 Washington Blvd, Suite 100Whittier, CA 90602 (562) 967‑2885
- 12555 Garden Grove Blvd, Suite 401Garden Grove, CA 92843 (909) 609‑5737
Group practices
Medicare enrollment lists David D. Nacionales as a member of these groups (CMS data updated October 2, 2026).
- PIH Health Physicians622 clinicians in the group
- Thrive Neurology PC2 clinicians in the group
Specialties
- Hospitalistprimary
- Neurologyalso
Other hospitalists in Downey
Clinicians with the same Medicare primary specialty in Downey, CA — not a recommendation.
Other clinicians in PIH Health Physicians
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | College Of Osteo Med Of The Pacific At Pomona |
| Graduation year | 2015 (11 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1699169227 |
| Corrections | Report an error or suggest an update → |
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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians