Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Althea Marie Fernandez Diaz, MD

Individual provider Allergy & Immunology Physician · NPI 1649838640

Althea Marie Fernandez Diaz, MD is an Allergy/Immunology in Brewster, New York. Graduated from New York Medical College in 2019, 7 years ago. Practices with Optum Medical Care PC, a 1,018-clinician group and accepts Medicare assignment. Licensed in New York.

Years since qualifying
7
Trained at
New York Medical College
Licensed in
NY
In the registry since
2019
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

185 Ny 312 Southeast Executive Park
Brewster, NY 10509
Phone: (845) 278-7000
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence 316128 (NY)
Internal Medicine Physician Taxonomy 207R00000X · Licence 316128 (NY)

Record details

NPI number1649838640
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 4, 2019
Last updated in NPPESApril 14, 2026
Certification dateApril 14, 2026

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyALLERGY/IMMUNOLOGY
Medical schoolNEW YORK MEDICAL COLLEGE
Graduated 2019 (7 years in practice)
Group practice Optum Medical Care Pc — 1018 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount