Zachary Nan
NPI 1598523755 · Internal Medicine Physician · Chicago, IL
Enrolled with Medicare as Order and Referring Only - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Zachary Nan is a Internal Medicine Physician provider in Chicago, IL (NPI 1598523755).
Provider details
- NPI number
- 1598523755
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Sex
- Male
- Sole proprietor
- Yes
- License
- 125.085699 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
2 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2024-03-11
- Last updated
- 2025-05-12
- Certified
- 2025-05-12
Frequently asked questions
- What is Zachary Nan's NPI number?
- Zachary Nan's National Provider Identifier (NPI) is 1598523755, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Zachary Nan's specialty?
- Zachary Nan is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Zachary Nan located?
- Zachary Nan's practice location on file with NPPES is 5841 S. Maryland Ave., Chicago, IL 60637-1443.
- What is Zachary Nan's phone number?
- The practice phone number listed in the NPPES registry for Zachary Nan is (774) 702-6840.
- Does Zachary Nan accept Medicare?
- Zachary Nan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Zachary Nan's NPI active?
- Yes — Zachary Nan's NPI (1598523755) is active in the NPPES registry as of the last update on 2025-05-12.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.