DR. DOROTHY J ZAJAC MD
NPI 1972592210
Internal Medicine in Chester, IL
About Dr. Dorothy J Zajac Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. DOROTHY J ZAJAC MD (NPI 1972592210) is an individual internal medicine provider in Chester, Illinois, licensed in Wisconsin (22841) and active in the NPI registry since October 2005. She is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Dr. Dorothy J Zajac Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignment
Medicare enrollment records show Dorothy Zajac reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Chester, IL 62233
- Reassigned Medicare billing, Illinois enrollment
- 46 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 62233 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 19
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
CHESTER, IL 62233
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Dorothy Zajac's NPI number?
The NPI number for Dorothy Zajac is 1972592210. It was assigned to this individual provider in the NPPES registry on October 19, 2005.
Where is Dorothy Zajac located?
Dorothy Zajac practices at 1315 Lehmen Dr, Chester, IL 62233. The listed phone number is (618) 826-4571.
What is Dorothy Zajac's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Dorothy Zajac enrolled in Medicare?
Yes. Dorothy Zajac is registered in the Medicare PECOS enrollment system.
Which organization bills Medicare for Dorothy Zajac's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Dorothy Zajac reassigns Medicare benefits to Illinois Department Of Human Services (Chester, IL). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Dorothy Zajac's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Dorothy Zajac was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. Dorothy J Zajac, MD · NPI 1972592210
Internal Medicine physician in Chester, Illinois. Individual provider, active in the CMS NPPES registry since October 19, 2005.
## Identity
- **NPI:** 1972592210 (Entity type: Individual)
- **Enumerated:** October 19, 2005
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **Sole proprietor:** No
## Practice location
- **Address:** 1315 LEHMEN DR, Chester, IL 62233-2542
- **Phone:** (618) 826-4571 · **Fax:** (618) 826-3229
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** Illinois Department Of Human Services (NPI 1306834726, Chester, IL), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** July 13, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1972592210) · Data from the CMS NPPES public registry.