Althea Marie Fernandez Diaz, MD
Allergy & Immunology Physician · Brewster, NY
Althea Marie Fernandez Diaz, MD is an allergy & immunology physician with a practice address in Brewster, New York, and NPI 1649838640, issued on Jun 4, 2019. Check the license (New York 316128, as entered in NPPES) on the NYS Education Department, Office of the Professions; the Medicare figures below come from public CMS files.
- Name
- Althea Marie Fernandez Diaz
- Credential
- MD
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License number
- 316128 NY
Self-reported in NPPES; status is on the state search - Practice location
- 185 NY 312 Southeast Executive Park, Brewster, NY 10509
- Phone
- (845) 278-7000
- Enumerated
- Jun 4, 2019
- Record last updated
- Apr 14, 2026
- Medicare enrollment
- Enrolled (PECOS I20240819000537); accepts Medicare assignment
- Medical or professional school
- New York Medical College, 2019
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 311 in New York → Look up another NPI →
Verify Althea Marie Fernandez Diaz in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersNYS Education Department, Office of the Professions
Search for license 316128Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
68% fewer Medicare Part D claims than the average allergy & immunology physician in 2024
238 Medicare Part D claims for 46 beneficiaries, against an average of 741 among the 2,899 providers of this specialty who prescribed in Part D. Brand-name drugs were 42% of claims.
Most prescribed
- Montelukast Sodium28 claims
- Levocetirizine Dihydrochloride26 claims
- Azelastine Hcl23 claims
- Fluticasone Propionate17 claims
- Hyqvia16 claims
- Epinephrine14 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Optum Medical Care PCMount Kisco, NY
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Althea Marie Fernandez Diaz among 311 allergy & immunology physician records in New York
Althea Marie Fernandez Diaz, MD is one of 311 allergy & immunology physician records with a practice address in New York. 84% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2019, is newer than 94% of them.
- NPI issued2019 · 94% of these records are older, 4% newer
- In a Medicare fileYes · 84% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated2019 · median 2000 among the 211 with a school on file
- Record last updated2026 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a New York practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in New York
There are 311 allergy & immunology physician records in New York.
All 311 in New York → Every provider in Brewster → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Haeyoung Hwang, M.D.Croton, NY 105201235235318
- Angela Chan, M.D.Harrison, NY 105281366805798
- Taya Carpenter, DOHawthorne, NY 105321316408461
- Iwona Dziewa, D.O.Jefferson Valley, NY 105351083091789
- Danna Chung, M.D.Mamaroneck, NY 105431881809952
- Roshini Mullakary, MDMamaroneck, NY 105431194119305
- Harvey Gorrin, MDMt Kisco, NY 105491740253186
- Lois Tuerk-Mendelsohn, M.D.Mount Kisco, NY 105491366466146
Common questions
What is Althea Marie Fernandez Diaz, MD's NPI number?
Althea Marie Fernandez Diaz, MD's National Provider Identifier (NPI) is 1649838640, issued on Jun 4, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Althea Marie Fernandez Diaz, MD located?
The NPPES record lists a practice address at 185 NY 312 Southeast Executive Park, Brewster, NY, 10509. Phone: (845) 278-7000. Providers update this record themselves, so call before visiting.
How can I verify Althea Marie Fernandez Diaz, MD's license?
NPPES lists New York license number 316128, as entered by the provider. Search the NYS Education Department, Office of the Professions at https://www.op.nysed.gov/services/verifications/online-verification-searches. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Althea Marie Fernandez Diaz, MD prescribe under Medicare Part D?
In 2024, Althea Marie Fernandez Diaz, MD had 238 Medicare Part D claims for 46 beneficiaries; the average among allergy & immunology physician prescribers was 741. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.