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

Mrs. Iryna G Chastain, MD

Individual provider Internal Medicine Physician · NPI 1285801407

Mrs. Iryna G Chastain, MD is an Internal Medicine in Worcester, Massachusetts. Qualified in 1997, 29 years ago. Practices with Reliant Medical Group Inc, a 638-clinician group and accepts Medicare assignment. Licensed in Massachusetts.

Years since qualifying
29
Licensed in
MA
In the registry since
2008
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

123 Summer St
Worcester, MA 01608-1216
Phone: (508) 363-5000
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 238742 (MA)

Record details

NPI number1285801407
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedMay 15, 2008
Last updated in NPPESMarch 9, 2020
Certification dateMarch 9, 2020

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 1997 (29 years in practice)
Group practice Reliant Medical Group Inc — 638 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

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