NATHAN ONTROP MD SC
NPI 1619498052
Psychiatry & Neurology - Psychiatry in Chicago, IL
About Nathan Ontrop Md Sc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
NATHAN ONTROP MD SC (NPI 1619498052) is a healthcare organization registered as a psychiatry in Chicago, Illinois and active in the NPI registry since July 2017. The organization lists Nathan Ontrop, President, as its authorized official.
NPPES Registry Identity
Specialties & Licenses
Group Practice 1
Medicare Participation & PECOS CMS
Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Nathan Ontrop Md Sc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Clinicians Billing Medicare Through This Organization
Medicare enrollment records show 1 clinician reassigns Medicare billing to Nathan Ontrop MD Sc, which bills Medicare for the services this clinician delivers.
Clinician (1)
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
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 Nathan Ontrop MD Sc's NPI number?
The NPI number for Nathan Ontrop MD Sc is 1619498052. It was assigned to this organization in the NPPES registry on July 6, 2017.
Where is Nathan Ontrop MD Sc located?
Nathan Ontrop MD Sc is located at 25 E Washington St Ste 1601, Chicago, IL 60602. The listed phone number is (312) 725-2347.
What is Nathan Ontrop MD Sc's specialty?
The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.
Is Nathan Ontrop MD Sc enrolled in Medicare?
Yes. Nathan Ontrop MD Sc is registered in the Medicare PECOS enrollment system.
How many clinicians bill Medicare through Nathan Ontrop MD Sc?
According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Psychiatry) reassigns their Medicare billing to Nathan Ontrop MD Sc. A 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 the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
When was this NPI record last updated?
The NPPES record for Nathan Ontrop MD Sc was last updated on May 22, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 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.
# Nathan Ontrop Md Sc · NPI 1619498052
Psychiatry organization in Chicago, Illinois. Organization record, active in the CMS NPPES registry since July 6, 2017.
## Identity
- **NPI:** 1619498052 (Entity type: Organization)
- **Enumerated:** July 6, 2017
- **Primary specialty:** Psychiatry & Neurology - Psychiatry · taxonomy 2084P0800X
- **Organization subpart:** No
- **Authorized official:** Nathan Ontrop, PRESIDENT
## Practice location
- **Address:** 25 E WASHINGTON ST STE 1601, Chicago, IL 60602
- **Phone:** (312) 725-2347
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Clinicians billing through this organization:** 1 clinician (Psychiatry) reassigns Medicare billing to this organization (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** May 22, 2018
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Source: [NPI Profile](https://npiprofile.com/npi/1619498052) · Data from the CMS NPPES public registry.