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ALTHEA MARIE FERNANDEZ DIAZ MD
NPI 1649838640
Allergy & Immunology in Brewster, NY

Active since June 04, 2019PECOS EnrolledAccepts Medicare Assignment
185 NY 312 SOUTHEAST EXECUTIVE PARK, BREWSTER, NY 10509(845) 278-7000 Get Directions Write a Review

NPPES record last updated: April 14, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Apr 14, 2026, Jul 8, 2024, Jun 4, 2019 (3 updates tracked since 2019).

About Althea Marie Fernandez Diaz Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

ALTHEA MARIE FERNANDEZ DIAZ MD (NPI 1649838640) is an individual allergy & immunology provider in Brewster, New York, licensed in New York (316128) and active in the NPI registry since June 2019. She is enrolled in Medicare PECOS and is a graduate of New York Medical College (2019).

NPPES Registry Identity

NPI1649838640
Entity TypeIndividualFemale
Primary Taxonomy207K00000X
Provider Legal NameALTHEA MARIE FERNANDEZ DIAZCredential: MD
Location Address185 NY 312 SOUTHEAST EXECUTIVE PARKBrewster, NY 10509
Mailing Address185 Route 312Brewster, NY 10509-2337 · (845) 278-7000
Phone(845) 278-7000
Sole ProprietorNo
Medical School CMSNew York Medical CollegeGraduated 2019
Enumeration DateJune 4, 2019
Last NPPES UpdateApril 14, 20263 updates tracked since enumeration
NPPES CertifiedApril 14, 2026
✔ NPI 1649838640 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyAllergy & ImmunologyAllopathic & Osteopathic Physicians
Taxonomy Code207K00000X
License✔ Licensed in NY · 316128
Definition
An allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Selected examples of such conditions include asthma, anaphylaxis, rhinitis, eczema, and adverse reactions to drugs, foods, and insect stings as well as immune deficiency diseases (both acquired and congenital), defects in host defense, and problems related to autoimmune disease, organ transplantation, or malignancies of the immune system.
Also ListedInternal MedicineTaxonomy 207R00000X · License 316128 (NY)
185 NY 312 SOUTHEAST EXECUTIVE PARK, Brewster, NY 10509
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Althea Marie Fernandez Diaz Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID3577001874
PECOS Enrollment IDI20240819000537
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Althea Marie Diaz's NPI number?

The NPI number for Althea Marie Diaz is 1649838640. It was assigned to this individual provider in the NPPES registry on June 4, 2019.

Where is Althea Marie Diaz located?

Althea Marie Diaz practices at 185 Ny 312 Southeast Executive Park, Brewster, NY 10509. The listed phone number is (845) 278-7000.

What is Althea Marie Diaz's specialty?

The primary specialty registered for this NPI is Allergy & Immunology with taxonomy code 207K00000X.

Is Althea Marie Diaz enrolled in Medicare?

Yes. Althea Marie Diaz is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

When was this NPI record last updated?

The NPPES record for Althea Marie Diaz was last updated on April 14, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.