Robert Day, M.D.
NPI 1841618634 · Maternal & Fetal Medicine Physician · Irvine, CA
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Robert Day, M.D. is a Maternal & Fetal Medicine Physician provider in Irvine, CA (NPI 1841618634).
Provider details
- NPI number
- 1841618634
- Entity type
- Individual
- Primary specialty
- Maternal & Fetal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A139689 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
12 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
2 documented practice locations
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.
Practice location
Mailing address
Additional practice locations (1)
- 700 Lawrence ExpySanta Clara, CA 95051-5173Phone: (408) 851-1000
Registry dates
- Enumerated
- 2014-03-31
- Last updated
- 2025-06-17
- Certified
- 2025-06-17
Frequently asked questions
- What is Robert Day's NPI number?
- Robert Day's National Provider Identifier (NPI) is 1841618634, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Robert Day's specialty?
- Robert Day is listed in the NPPES registry with a primary specialty of Maternal & Fetal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Robert Day located?
- Robert Day's practice location on file with NPPES is 16305 Sand Canyon Ave Ste 225, Irvine, CA 92618-3795.
- What is Robert Day's phone number?
- The practice phone number listed in the NPPES registry for Robert Day is (949) 763-7451.
- Does Robert Day accept Medicare?
- Robert Day is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Robert Day's NPI active?
- Yes — Robert Day's NPI (1841618634) is active in the NPPES registry as of the last update on 2025-06-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.