Jay A. Keystone, M.D.

Allergy & Immunology

Internal Medicine

Jay A. Keystone is an Allergy & Immunology specialist based in Vacaville, CA with over 56 years of clinical experience. Offers virtual telehealth visits.

(707) 446-8581Vacaville, CA
Telehealth Available
NPI Active per CMS — Q2 2026

With over 56 years in internal medicine, Jay a. Keystone, M.D. is a long-established allergy & immunology specialist in Vacaville. He graduated from University of Michigan Medical School in 1970 and has 56+ years of clinical experience. An internist doctor of osteopathy that specializes in the treatment of allergy and immunologic disorders.

1 of 27 Internal Medicine providers in CASee all Internal Medicine in Vacaville56+ years experienceNPI since 2011

Older · 2236dNPPES updated 2020-04-09 · verify NPI on CMS · Verify license at Medical Board of California

Contact & Location

Practice Location

365 Evergreen Dr, Vacaville, CA 95688-2136

Fax: (707) 446-8581

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Background & Specialty

Education, training, and specialty classification from CMS NPPES and Medicare records.

Career Journey
  1. Graduated medical school · 1970

    University of Michigan Medical School

  2. Board certified · Apr 8, 2020

    Self-reported via NPPES

  3. 56 years in practice

    Senior practitioner

Internal MedicineAllergy & Immunology in VacavilleAllopathic & Osteopathic Physicians

An internist doctor of osteopathy that specializes in the treatment of allergy and immunologic disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine can obtain a Certificate of Special Qualifications in the field of Allergy & Immunology.

Taxonomy: 207RA0201X

Education & Training

University of Michigan Medical School (Class of 1970)

Virtual Allergy & Immunology Care With Jay a. Keystone

NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.

Schedule a virtual visit with Jay a. Keystone for follow-ups, medication reviews, and ongoing care — no travel to Vacaville required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes.

Frequently Asked Questions

Common questions about Jay a. Keystone

Dr. Keystone is listed as active in the NPI registry with telehealth listed in Vacaville, CA. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (707) 446-8581.

Verified across 2 federal data sources

Sourced from CMS NPPES · OIG LEIE. See Data Methodology.

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Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.

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