Michael Chien, MD
NPI 1689741555 · Allergy Physician · Fontana, CA
Enrolled with Medicare as Practitioner - Allergy/Immunology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Chien, MD is a Allergy Physician provider in Fontana, CA (NPI 1689741555).
Provider details
- NPI number
- 1689741555
- Entity type
- Individual
- Primary specialty
- Allergy PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G70196 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$112 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-11-29
- Last updated
- 2021-11-29
Frequently asked questions
- What is Michael Chien's NPI number?
- Michael Chien's National Provider Identifier (NPI) is 1689741555, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Chien's specialty?
- Michael Chien is listed in the NPPES registry with a primary specialty of Allergy Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Chien located?
- Michael Chien's practice location on file with NPPES is 9961 Sierra Ave, Fontana, CA 92335-6720.
- What is Michael Chien's phone number?
- The practice phone number listed in the NPPES registry for Michael Chien is (909) 427-3910.
- Does Michael Chien accept Medicare?
- Michael Chien is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Chien's NPI active?
- Yes — Michael Chien's NPI (1689741555) is active in the NPPES registry as of the last update on 2021-11-29.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.