Mrs Iryna G Chastain, MD - Medicare Internal Medicine in Worcester, MA

Mrs Iryna G Chastain, MD is a medicare enrolled "Internal Medicine" physician in Worcester, Massachusetts. She graduated from medical school in 1997 and has 27 years of diverse experience with area of expertise as Internal Medicine. She is a member of the group practice Reliant Medical Group Inc and her current practice location is 123 Summer St, Worcester, Massachusetts. You can reach out to her office (for appointments etc.) via phone at (508) 363-5000.

Mrs Iryna G Chastain is licensed to practice in Massachusetts (license number 238742) and she also participates in the medicare program. She accepts medicare assignments (which means she accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance) and her NPI Number is 1285801407.

Contact Information

Mrs Iryna G Chastain, MD
123 Summer St,
Worcester, MA 01608-1216
(508) 363-5000
Not Available

Map and Direction




Physician's Profile

Full NameMrs Iryna G Chastain
GenderFemale
SpecialityInternal Medicine
Experience27 Years
Location123 Summer St, Worcester, Massachusetts
Accepts Medicare AssignmentsYes. She accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance.
  Medical Education and Training:
  • Mrs Iryna G Chastain graduated from medical school in 1997
  NPI Data:
  • NPI Number: 1285801407
  • Provider Enumeration Date: 05/15/2008
  • Last Update Date: 03/09/2020
  Medicare PECOS Information:
  • PECOS PAC ID: 7618028606
  • Enrollment ID: I20090702000539

Medical Identifiers

Medical identifiers for Mrs Iryna G Chastain such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1285801407NPI-NPPES
110083584AMedicaidMA

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
207R00000XInternal Medicine 238742 (Massachusetts)Primary

Medical Facilities Affiliation

Facility NameLocationFacility Type
St Vincent HospitalWorcester, MAHospital

Group Practice Association

Group Practice NameGroup PECOS PAC IDNo. of Members
Reliant Medical Group Inc5597755322546

Medicare Reassignments

Some practitioners may not bill the customers directly but medicare billing happens through clinics / group practice / hospitals where the provider works. Medicare reassignment of benefits is a mechanism by which practitioners allow third parties to bill and receive payment for medicare services performed by them. Mrs Iryna G Chastain allows following entities to bill medicare on her behalf.
Entity NameReliant Medical Group Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1720017528
PECOS PAC ID: 5597755322
Enrollment ID: O20040708000650
Entity NameSteward Medical Group Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1629398219
PECOS PAC ID: 2860688728
Enrollment ID: O20101119000332
Entity NamePhysicians Of Cape Cod Hospital
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1679832364
PECOS PAC ID: 9638326671
Enrollment ID: O20120828000193
Entity NameVibra Physicians Llc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1659705424
PECOS PAC ID: 8921233933
Enrollment ID: O20140213000276

Medicare Part D Prescriber Enrollment

Any physician or other eligible professional who prescribes Part D drugs must either enroll in the Medicare program or opt out in order to prescribe drugs to their patients with Part D prescription drug benefit plans. Mrs Iryna G Chastain is enrolled with medicare and thus, if eligible, can prescribe medicare part D drugs to patients with medicare part D benefits.

Mailing Address and Practice Location

Mailing AddressPractice Location Address
Mrs Iryna G Chastain, MD
5 Neponset Street, Wot 2nd Fl, Ste C203,
Worcester, MA 01606-2714

Ph: (508) 852-0600
Mrs Iryna G Chastain, MD
123 Summer St,
Worcester, MA 01608-1216

Ph: (508) 363-5000

Reviews and Comments


Internal Medicine Doctors in Worcester, MA

Dr. Adepeju Gbadebo Champion, M.D.
Internal Medicine
Medicare: Not Enrolled in Medicare
Practice Location: 55 Lake Ave N, Worcester, MA 01655
Phone: 508-334-2731    Fax: 774-442-4672
Madaiah Lokeshwari, M.D.
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Medicare: Accepting Medicare Assignments
Practice Location: 123 Summer St, Worcester, MA 01608
Phone: 508-363-6849    
Sowmya Korapati,
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 55 Lake Ave N, Worcester, MA 01655
Phone: 508-334-3550    Fax: 774-442-6715
Irma Nadeem Hashmi, DO
Internal Medicine
Medicare: Medicare Enrolled
Practice Location: 55 Lake Ave N, Worcester, MA 01655
Phone: 508-334-1000    
Dr. Madhav Sharma, MD
Internal Medicine
Medicare: Medicare Enrolled
Practice Location: 123 Summer St, Worcester, MA 01608
Phone: 508-363-5438    
Daniel M Steigman, MD
Internal Medicine
Medicare: Medicare Enrolled
Practice Location: 123 Summer Street, Suite 390, Worcester, MA 01608
Phone: 508-368-3120    Fax: 508-368-3121
Dr. Julia D Andrieni, M.D.
Internal Medicine
Medicare: Not Enrolled in Medicare
Practice Location: 55 Lake Ave N, Department Of General Medicine, Worcester, MA 01655
Phone: 508-334-2731    

Medicare Program: Medicare is a federal government program which provides health insurance to people who are 65 or older. This program also covers certain younger people with disabilities (who receive Social Security Disability Insurance - SSDI), and people with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant, sometimes called ESRD.

Medicare Assignment: Assignment means that your doctor, provider, or supplier agrees (or is required by law) to accept the Medicare-approved amount as full payment for covered services. Most doctors, providers, and suppliers accept assignment, but you should always check to make sure. Participating providers have signed an agreement to accept assignment for all Medicare-covered services.

NPI Number: The National Provider Identifier (NPI) is a unique identification number for covered health care providers. The NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions. Covered health care providers and all health plans and health care clearinghouses must use the NPIs in the administrative and financial transactions adopted under HIPAA (Health Insurance Portability and Accountability Act).

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