IndividualActive
Mark Zajackowski, MD
NPI 1578857264 · General Practice Physician · Chicago, IL
Mark Zajackowski, MD is a General Practice Physician provider in Chicago, IL (NPI 1578857264).
Provider details
- NPI number
- 1578857264
- Entity type
- Individual
- Primary specialty
- General Practice PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- Yes
- License
- 036-051907 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
Detailed profile(81/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
15 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
5445 N Sheridan Rd
#3102
Chicago, IL 60640-1957
Phone: (773) 271-0609
Street-level locationGet directions
Mailing address
5445 N Sheridan Rd
Chicago, IL 60640-1957
Registry dates
- Enumerated
- 2011-05-31
- Last updated
- 2011-05-31
Frequently asked questions
- What is Mark Zajackowski's NPI number?
- Mark Zajackowski's National Provider Identifier (NPI) is 1578857264, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Zajackowski's specialty?
- Mark Zajackowski is listed in the NPPES registry with a primary specialty of General Practice Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Zajackowski located?
- Mark Zajackowski's practice location on file with NPPES is 5445 N Sheridan Rd, Chicago, IL 60640-1957.
- What is Mark Zajackowski's phone number?
- The practice phone number listed in the NPPES registry for Mark Zajackowski is (773) 271-0609.
- Is Mark Zajackowski's NPI active?
- Yes — Mark Zajackowski's NPI (1578857264) is active in the NPPES registry as of the last update on 2011-05-31.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.