Gregory Paul Zydiak, M.D.
Internal Medicine Physician · Webster Groves, MO
Gregory Paul Zydiak, M.D. is an internal medicine physician with a practice address in Webster Groves, Missouri, and NPI 1740317155, issued on Feb 27, 2007. Check the license (Missouri R6E13, as entered in NPPES) on the Missouri Board of Registration for the Healing Arts; the Medicare figures below come from public CMS files.
- Name
- Gregory Paul Zydiak
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- R6E13 MO
Self-reported in NPPES; status is on the state search - Practice location
- 415 Oak Tree Dr, Webster Groves, MO 63119
- Phone
- (314) 351-6189
- Enumerated
- Feb 27, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (314) 968-4369
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,604 in Missouri → Look up another NPI →
Verify Gregory Paul Zydiak in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMissouri Board of Registration for the Healing Arts
Search for license R6E13Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
57% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,364 Medicare Part D claims for 74 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims. 33 claims were for opioids.
Most prescribed
- Trazodone Hcl88 claims
- Furosemide66 claims
- Atorvastatin Calcium63 claims
- Potassium Chloride61 claims
- Lisinopril54 claims
- Omeprazole49 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.
Gregory Paul Zydiak among 2,604 internal medicine physician records in Missouri
Gregory Paul Zydiak, M.D. is one of 2,604 internal medicine physician records with a practice address in Missouri. 77% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 41% of them.
- NPI issued2007 · 41% of these records are older, 53% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileNo · 55% of these records are
- Record last updated2007 · 48% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Missouri practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Internal Medicine Physician providers in Missouri
There are 2,604 internal medicine physician records in Missouri.
All 2,604 in Missouri → Every provider in Webster Groves → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Hebri Ballal, M.D.Saint Louis, MO 631191871587931
- Brian Bergfeld, M.D.Saint Louis, MO 631191750375812
- Bradley Bernhard, M.D.Saint Louis, MO 631191538153606
- William Budd, M.D.Saint Louis, MO 631191861486953
- Sunny Desai, M.D.Saint Louis, MO 631191306830492
- Mark Fogarty, M.D.Saint Louis, MO 631191770577736
- Matthew Hill, MDSaint Louis, MO 631191497701569
- Christine Hoffner-Owens, D.O.Saint Louis, MO 631191073591772
Common questions
What is Gregory Paul Zydiak, M.D.'s NPI number?
Gregory Paul Zydiak, M.D.'s National Provider Identifier (NPI) is 1740317155, issued on Feb 27, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Gregory Paul Zydiak, M.D. located?
The NPPES record lists a practice address at 415 Oak Tree Dr, Webster Groves, MO, 63119. Phone: (314) 351-6189. Providers update this record themselves, so call before visiting.
How can I verify Gregory Paul Zydiak, M.D.'s license?
NPPES lists Missouri license number R6E13, as entered by the provider. Search the Missouri Board of Registration for the Healing Arts at https://www.fsmb.org/contact-a-state-medical-board/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gregory Paul Zydiak, M.D. prescribe under Medicare Part D?
In 2024, Gregory Paul Zydiak, M.D. had 1,364 Medicare Part D claims for 74 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.