DR. RONALD ANTHONY ZIMMERMANN D.O.
NPI 1346404985
Hospitalist in Naperville, IL
About Dr. Ronald Anthony Zimmermann D.o. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. RONALD ANTHONY ZIMMERMANN D.O. (NPI 1346404985) is an individual hospitalist provider in Naperville, Illinois, licensed in Illinois (036.128777) and active in the NPI registry since July 2008. He is enrolled in Medicare PECOS, is affiliated with Copley Memorial Hospital, and maintains 4 additional practice locations.
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Locations 4
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. Ronald Anthony Zimmermann D.o. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
9Medicare enrollment records show Ronald Zimmermann reassigns Medicare billing to 9 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Naperville, IL 60540
- Reassigned Medicare billing, Illinois enrollment
- 561 clinicians in this Medicare group
Downers Grove, IL 60515
- Reassigned Medicare billing, Illinois enrollment
- 4,870 clinicians in this Medicare group
Evanston, IL 60201
- Reassigned Medicare billing, Illinois enrollment
- 4,841 clinicians in this Medicare group
Ottawa, IL 61350
- Reassigned Medicare billing, Illinois enrollment
- 233 clinicians in this Medicare group
Rockford, IL 61104
- Reassigned Medicare billing, Illinois enrollment
- 69 clinicians in this Medicare group
Normal, IL 61761
- Reassigned Medicare billing, Illinois enrollment
- 698 clinicians in this Medicare group
Quincy, IL 62301
- Reassigned Medicare billing, Illinois enrollment
- 81 clinicians in this Medicare group
Bridgeton, MO 63044
- Reassigned Medicare billing, Illinois enrollment
- 419 clinicians in this Medicare group
Carbondale, IL 62901
- Reassigned Medicare billing, Illinois enrollment
- 702 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.
Areas of Expertise CMS Part B claims 4
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare 4
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Copley Memorial Hospital
Acute Care Hospitals · Aurora, ILOsf Sacred Heart Medical Center
Acute Care Hospitals · Danville, ILSwedish Hospital
Acute Care Hospitals · Chicago, ILEdward Hospital
Acute Care Hospitals · Naperville, ILPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 60540 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 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
NAPERVILLE, IL 60540
NAPERVILLE, IL 60540
NAPERVILLE, IL 60540
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 Ronald Zimmermann's NPI number?
The NPI number for Ronald Zimmermann is 1346404985. It was assigned to this individual provider in the NPPES registry on July 14, 2008.
Where is Ronald Zimmermann located?
Ronald Zimmermann practices at 801 S Washington St, Naperville, IL 60540. The listed phone number is (630) 646-8704.
What is Ronald Zimmermann's specialty?
The primary specialty registered for this NPI is Hospitalist with taxonomy code 208M00000X.
Is Ronald Zimmermann enrolled in Medicare?
Yes. Ronald Zimmermann is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Ronald Zimmermann's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ronald Zimmermann reassigns Medicare benefits to 9 organizations: Edward Health Ventures (Naperville, IL), Advocate Health And Hospitals Corporation (Downers Grove, IL), Endeavor Health Medical Group (Evanston, IL), 24 On Physicians, PC (Ottawa, IL), Rockford Hospitalist Group, LLC (Rockford, IL) and 4 more organizations, listed in the Medicare section above. Each 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 Ronald Zimmermann's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Ronald Zimmermann affiliated with any hospitals?
According to CMS data, Ronald Zimmermann is affiliated with Copley Memorial Hospital, Osf Sacred Heart Medical Center, Swedish Hospital and Edward Hospital.
When was this NPI record last updated?
The NPPES record for Ronald Zimmermann was last updated on December 10, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years 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. Ronald Anthony Zimmermann, D.O. · NPI 1346404985
Hospitalist physician in Naperville, Illinois. Individual provider, active in the CMS NPPES registry since July 14, 2008.
## Identity
- **NPI:** 1346404985 (Entity type: Individual)
- **Enumerated:** July 14, 2008
- **Primary specialty:** Hospitalist · taxonomy 208M00000X
- **State license:** 036.128777 (Illinois)
- **Sole proprietor:** No
## Practice location
- **Address:** 801 S WASHINGTON ST, Naperville, IL 60540-7430
- **Phone:** (630) 646-8704
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 9 organizations under Medicare reassignment (form CMS-855R): Edward Health Ventures (NPI 1063830081, Naperville, IL); Advocate Health And Hospitals Corporation (NPI 1285903849, Downers Grove, IL); Endeavor Health Medical Group (NPI 1497701882, Evanston, IL); 24 On Physicians, PC (NPI 1346480431, Ottawa, IL); Rockford Hospitalist Group, LLC (NPI 1750088852, Rockford, IL); and 4 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Lake Erie College Of Osteopathic Medicine, Erie, class of 2008
## Record status
- **NPPES last updated:** December 10, 2021
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Source: [NPI Profile](https://npiprofile.com/npi/1346404985) · Data from the CMS NPPES public registry.