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Allergy/Immunology

Denis J. Yoshii, DO

Sees patients in Costa Mesa, CA · California

Summary

Dr. Denis J. Yoshii, DO is an allergist and immunologist at 1700 Adams Ave, Suite 100, Costa Mesa, CA 92626. Phone: (714) 549-0301. May accept Medicare assignment. In 2024, Denis J. Yoshii had 53 Original Medicare patients and 1,734 services. NPI 1124091814. Source: CMS National Downloadable File, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Allergist and immunologist (Medicare lists Allergy/Immunology)
  • Address: 1700 Adams Ave, Suite 100, Costa Mesa, CA 92626 · Directions
  • Phone: (714) 549‑0301
  • Medicare: May accept Medicare assignment
  • Medical school: graduated 1995 (31 years since medical school)
  • Gender (as listed): Male

From official Medicare data

This page shows what Medicare's official clinician data says about Denis J. Yoshii, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Denis J. Yoshii accept Medicare assignment?
Medicare's clinician data says Denis J. Yoshii may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
How many Medicare patients does Denis J. Yoshii see?
In 2024, CMS data shows 53 Original Medicare patients and 1,734 services for Denis J. Yoshii. This counts Original Medicare only and measures volume, not quality.
What is Denis J. Yoshii's NPI number?
1124091814. 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 Denis J. Yoshii, 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 patients53
Services billed to Medicare1,734
Different services or procedures15
Participating Medicare providerYes
Average age of these patients73

Most frequent services

  1. Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)51 services
  2. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)27 services
  3. Test to measure expiratory airflow and volume (94010)16 services
  4. New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)12 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 pressure74%
  • Arthritis62%
  • Asthma43%
  • Diabetes25%
  • Ischemic heart disease25%

Practice locations

Addresses where Denis J. Yoshii is enrolled with Medicare (CMS data updated October 2, 2026).

Specialties

Find other Allergy/Immunology doctors in California →

Other allergist and immunologists in California

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

All allergist and immunologists in California →

Clinician information

CredentialDO
Graduation year1995 (31 years since medical school)
Gender (as listed)Male
Medicare assignmentMay accept for some services
NPI (National Provider Identifier)1124091814
CorrectionsReport 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

  1. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  2. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians