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Dr. Gregory W Siewny, MD

Obstetrics & Gynecology Physician in Franklin, OH · enumerated 2005.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1891791216

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Registry record

Entity type Individual (Type 1)
Name Dr. Gregory W Siewny
Credential MD
Sex Male
Practice address 200 Medical Center Dr, Suite 160, Franklin, OH, 45005
Phone (513) 424-1440
Fax (513) 424-1422
Enumeration date Jun 21, 2005
Last updated in NPPES Apr 24, 2015

Taxonomy & licenses

207V00000X Obstetrics & Gynecology Physician Allopathic & Osteopathic Physicians · License 35049923 (OH) Primary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier Type State Issuer
641361 Other OH AETNA
0542354 Medicaid OH -
311236707 Other OH FHP HEALTH PLAN
4992306 Other OH CHOICE CARE
0720009 Other OH UHC
0720009 Other OH JF MOLLOY
000000275779 Other OH ANTHEM
160009443 Other OH MEDICARE RAILROAD
5845285001 Other OH CIGNA

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

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Frequently asked questions

What is the NPI number for Gregory Siewny?
The National Provider Identifier (NPI) for Gregory Siewny is 1891791216, a Type 1 (individual) record in the CMS NPPES registry.
Where does Gregory Siewny practice?
The practice location on file with NPPES is in Franklin, OH. Providers can have multiple locations; NPPES lists the primary practice address.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2015-04-24.