Gregory Zydiak, M.D.
NPI 1740317155 · Internal Medicine Physician · Webster Groves, MO
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Zydiak, M.D. is a Internal Medicine Physician provider in Webster Groves, MO (NPI 1740317155).
Provider details
- NPI number
- 1740317155
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- R6E13 (MO)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
424 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 356 | $69 |
| Initial Nursing Facility Care With High Level of Medical Decision Making, Per Day, If Using Time, 50 Minutes Or More99306 | 36 | $169 |
| Subsequent Nursing Facility Care With Moderate Level of Medical Decision Making, Per Day, If Using Time, at Least 30 Minutes99309 | 32 | $99 |
Typical Medicare-allowed amounts for these services range $69–$169 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 43 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Trazodone Hcl | 88 | — |
| Furosemide | 66 | — |
| Atorvastatin Calcium | 63 | — |
| Potassium Chloride | 61 | 11 |
| Lisinopril | 54 | — |
| Omeprazole | 49 | — |
| Famotidine | 48 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-02-27
- Last updated
- 2007-07-08
Frequently asked questions
- What is Gregory Zydiak's NPI number?
- Gregory Zydiak's National Provider Identifier (NPI) is 1740317155, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Zydiak's specialty?
- Gregory Zydiak is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Gregory Zydiak located?
- Gregory Zydiak's practice location on file with NPPES is 415 Oak Tree Dr, Webster Groves, MO 63119-4848.
- What is Gregory Zydiak's phone number?
- The practice phone number listed in the NPPES registry for Gregory Zydiak is (314) 351-6189.
- Does Gregory Zydiak accept Medicare?
- Gregory Zydiak is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Zydiak's NPI active?
- Yes — Gregory Zydiak's NPI (1740317155) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.