Mark Zaydman, MD
NPI 1588017842 · Clinical Pathology Physician · Saint Louis, MO
Enrolled with Medicare as Practitioner - Pathology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Zaydman, MD is a Clinical Pathology Physician provider in Saint Louis, MO (NPI 1588017842).
Provider details
- NPI number
- 1588017842
- Entity type
- Individual
- Primary specialty
- Clinical Pathology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 2021030731 (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
9 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
1,638 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) |
|---|---|---|
| Protein Measurement, Serum84165 | 929 | $17 |
| Immunologic Analysis Technique on Serum (immunofixation)86334 | 493 | $17 |
| Immunologic Analysis Technique on Body Fluid, Other Fluids With Concentration86335 | 132 | $17 |
| Protein Measurement, Body Fluid84166 | 84 | $17 |
Typical Medicare-allowed amounts for these services range $17–$17 (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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2016-07-21
- Last updated
- 2025-04-17
- Certified
- 2021-11-23
Frequently asked questions
- What is Mark Zaydman's NPI number?
- Mark Zaydman's National Provider Identifier (NPI) is 1588017842, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Zaydman's specialty?
- Mark Zaydman is listed in the NPPES registry with a primary specialty of Clinical Pathology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Zaydman located?
- Mark Zaydman's practice location on file with NPPES is 1 Barnes Jewish Hospital Plz, Saint Louis, MO 63110-1003.
- What is Mark Zaydman's phone number?
- The practice phone number listed in the NPPES registry for Mark Zaydman is (314) 362-5641.
- Does Mark Zaydman accept Medicare?
- Mark Zaydman is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Zaydman's NPI active?
- Yes — Mark Zaydman's NPI (1588017842) is active in the NPPES registry as of the last update on 2025-04-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.