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DR. NATHAN D ONTROP M.D.
NPI 1760778468
Psychiatry & Neurology - Psychiatry in Chicago, IL

Active since June 22, 2011PECOS EnrolledAccepts Medicare Assignment
25 E WASHINGTON ST STE 1601, CHICAGO, IL 60602(312) 725-2347(312) 577-1574 Get Directions Write a Review

NPPES record last updated: August 7, 2025. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Aug 7, 2025, Jul 28, 2022, Apr 19, 2022 and 1 more (4 updates tracked since 2018).

About Dr. Nathan D Ontrop M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. NATHAN D ONTROP M.D. (NPI 1760778468) is an individual psychiatry provider in Chicago, Illinois, licensed in Illinois (036133952) and active in the NPI registry since June 2011. He is enrolled in Medicare PECOS, is affiliated with Osf Saint Elizabeth Mdl Ctr, and maintains a secondary practice location in Chicago.

NPPES Registry Identity

NPI1760778468
Entity TypeIndividualMale
Primary Taxonomy2084P0800X
Provider Legal NameDR. NATHAN D ONTROPCredential: M.D.
Location Address25 E WASHINGTON ST STE 1601Chicago, IL 60602
Mailing Address25 E Washington St Ste 1601Chicago, IL 60602-1882 · (312) 725-2347 · Fax (312) 577-1574
Phone(312) 725-2347
Fax(312) 577-1574
Sole ProprietorYes
Medical School CMSLoyola University Of Chicago, Stritch School Of MedicineGraduated 2011
Enumeration DateJune 22, 2011
Last NPPES UpdateAugust 7, 20254 updates tracked since enumeration
NPPES CertifiedAugust 7, 2025
✔ NPI 1760778468 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychiatry & Neurology · PsychiatryAllopathic & Osteopathic Physicians
Taxonomy Code2084P0800X
Licenses✔ Licensed in IL · 036133952✔ Licensed in IL · 125059575
Definition
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.
25 E WASHINGTON ST STE 1601, Chicago, IL 60602
Open in Google Maps ↗

Secondary Practice Location 1

Location 1836 W Wellington AveChicago, IL 60657-5147 · Phone (773) 296-3220 · Fax (773) 296-3226

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. Nathan D Ontrop M.d. 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.

PECOS PAC ID7911219829
PECOS Enrollment IDI20150707001683
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

5

Medicare enrollment records show Nathan Ontrop reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Nathan Ontrop MD Sc
0.1 mi
Psychiatry
25 E WASHINGTON ST STE 1601
Chicago, IL 60602
  • Reassigned Medicare billing, Illinois enrollment
NPI 1619498052 (312) 725-2347
Advocate Health And Hospitals Corp.
4.4 mi
Cardiovascular Disease
3118 N ASHLAND AVE
Chicago, IL 60657
  • Reassigned Medicare billing, Illinois enrollment
  • 4,870 clinicians in this Medicare group
NPI 1487951711 (773) 880-9722
Ottawa Regional Hospital & Healthcare Center
72 mi
General Acute Care Hospital
1100 E NORRIS DR
Ottawa, IL 61350
  • Reassigned Medicare billing, Illinois enrollment
  • 130 clinicians in this Medicare group
NPI 1306971080 (815) 433-3100
Carle West Physician Group Inc
119 mi
Family Medicine
1302 FRANKLIN AVE STE 3400
Normal, IL 61761
  • Reassigned Medicare billing, Illinois enrollment
  • 698 clinicians in this Medicare group
NPI 1467074138 (309) 556-8295
Osf Multi-Specialty Group
130 mi
Internal Medicine
8600 N STATE ROUTE 91
Peoria, IL 61615
  • Reassigned Medicare billing, Illinois enrollment
  • 2,944 clinicians in this Medicare group
NPI 1154908929 (309) 683-5050

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 5

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
235 services48 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
37 services19 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
35 services30 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
34 services27 patients
Hospital discharge day management, 30 minutes or less 99238
Hospital discharge day management of 30 minutes or less includes finalizing your treatment, discussing your progress, and planning after-care at home. It ensures you're ready to leave the hospital and continue recovery safely.
14 services13 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Osf Saint Elizabeth Mdl Ctr

Acute Care Hospitals · Ottawa, IL
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140110
Location1100 E Norris DriveOttawa, IL 61350 · La Salle County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 60602 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$183.39 typical visit price
range $60.08 – $183.39
Typical copayment $45.84 (range $15.02 – $45.84)
Most-billed visit code 99205
Established Patient
$74.80 typical visit price
range $18.97 – $148.12
Typical copayment $18.70 (range $4.74 – $37.03)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 11

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

CYNTHIA HAYES LCSW
Social Worker (Clinical)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 967-8918
MRS. KATIE MARIE EDWARDS-HUMPAL NP-C
Nurse Practitioner (Family)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 999-7809
MARY CATHERINE CHASE
Social Worker
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 500-7795
DR. ALECIA HURLEY DNP, APRN, PMHNP
Nurse Practitioner (Psychiatric/Mental Health)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 999-7809
LUMOS COUNSELING, PLLC
Social Worker (Clinical)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (224) 715-2030
DEANNE MARIE PISARKIEWICZ MD
Psychiatry & Neurology (Psychiatry)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 999-7809
NATHAN ONTROP MD SC
Psychiatry & Neurology (Psychiatry)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 725-2347
MODERN MENTAL HEALTH BY DR. ZACHARY KORDIK, PLLC
Psychiatry & Neurology (Psychiatry)
25 E WASHINGTON ST STE 1601
CHICAGO, IL 60602
Cook County (312) 566-7936

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's NPI number?

The NPI number for Nathan Ontrop is 1760778468. It was assigned to this individual provider in the NPPES registry on June 22, 2011.

Where is Nathan Ontrop located?

Nathan Ontrop practices at 25 E Washington St Ste 1601, Chicago, IL 60602. The listed phone number is (312) 725-2347.

What is Nathan Ontrop's specialty?

The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.

Is Nathan Ontrop enrolled in Medicare?

Yes. Nathan Ontrop 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 Nathan Ontrop's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Nathan Ontrop reassigns Medicare benefits to 5 organizations: Nathan Ontrop MD Sc (Chicago, IL), Advocate Health And Hospitals Corp. (Chicago, IL), Ottawa Regional Hospital & Healthcare Center (Ottawa, IL), Carle West Physician Group Inc (Normal, IL) and Osf Multi-Specialty Group (Peoria, IL). 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 Nathan Ontrop's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

Is Nathan Ontrop affiliated with any hospitals?

According to CMS data, Nathan Ontrop is affiliated with Osf Saint Elizabeth Mdl Ctr.

When was this NPI record last updated?

The NPPES record for Nathan Ontrop was last updated on August 7, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 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.