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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

TIMOTHY SEIJUNG OH MD
NPI 1750840856
Internal Medicine - Hematology in Evanston, IL

Active since March 18, 2019PECOS Enrolled
94.1/100
CMS Quality Rating
2650 RIDGE AVE, EVANSTON, IL 60201(847) 570-2112(847) 570-1041 Get Directions Write a Review

NPPES record last updated: October 22, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jul 9, 2026, Aug 16, 2022, Jun 17, 2019 and 1 more (4 updates tracked since 2019).

About Timothy Seijung Oh Md NPPES

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

TIMOTHY SEIJUNG OH MD (NPI 1750840856) is an individual hematology provider in Evanston, Illinois, licensed in Illinois (036159429) and active in the NPI registry since March 2019. He is enrolled in Medicare PECOS, maintains a secondary practice location in Chicago, and is a graduate of Wake Forest University School Of Medicine (2019).

NPPES Registry Identity

NPI1750840856
Entity TypeIndividualMale
Primary Taxonomy207RH0000X
Provider Legal NameTIMOTHY SEIJUNG OHCredential: MD
Location Address2650 RIDGE AVEEvanston, IL 60201-1700
Mailing Address2650 Ridge Ave Ste 1223Evanston, IL 60201-1700 · (847) 570-2040 · Fax (847) 733-5315
Phone(847) 570-2112
Fax(847) 570-1041
Sole ProprietorNo
Medical School CMSWake Forest University School Of MedicineGraduated 2019
Enumeration DateMarch 18, 2019
Last NPPES UpdateOctober 22, 20264 updates tracked since enumeration
NPPES CertifiedOctober 22, 2026
✔ NPI 1750840856 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 4

★ Primary SpecialtyInternal Medicine · HematologyAllopathic & Osteopathic Physicians
Taxonomy Code207RH0000X
License✔ Licensed in IL · 036159429
Definition
An internist with additional training who specializes in diseases of the blood, spleen and lymph. This specialist treats conditions such as anemia, clotting disorders, sickle cell disease, hemophilia, leukemia and lymphoma.
Also ListedInternal MedicineTaxonomy 207R00000X · License 036159429 (IL)
Also ListedInternal Medicine · Hematology & OncologyTaxonomy 207RH0003X · License 036159429 (IL)
Also ListedHospitalistTaxonomy 208M00000X · License 036159429 (IL)
2650 RIDGE AVE, Evanston, IL 60201
Open in Google Maps ↗

Secondary Practice Location 1

Location 1251 E Huron StChicago, IL 60611-3055 · Phone (312) 926-2000

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter Health, Ambetter Health of Delaware, Oscar Health.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Timothy Seijung Oh Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID8729313168
PECOS Enrollment IDI20260601002069
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 Reassignment

Medicare enrollment records show Timothy Oh reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Endeavor Health Medical Group
Same address
Anesthesiology
2650 RIDGE AVE, ANESTHESIOLOGY ROOM 3905
Evanston, IL 60201
  • Reassigned Medicare billing, Illinois enrollment
  • 4,841 clinicians in this Medicare group
NPI 1265695944 (847) 570-2760

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 60201 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
$105.70 typical visit price
range $18.97 – $148.12
Typical copayment $26.42 (range $4.74 – $37.03)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

94.1/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored through an Alternative Payment Model
Quality82.59
Promoting Interoperability100
Improvement Activities40

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.

DR. THOMAS LEE CIBULL M.D.
Pathology (Anatomic Pathology & Clinical Pathology)
2650 RIDGE AVE, EVANSTON HOSPITAL
EVANSTON, IL 60201
Cook County (847) 570-2040
LAUREN ANDERSON MD
Hospitalist
2650 RIDGE AVE
EVANSTON, IL 60201
Cook County (847) 570-1027
DR. DANIEL K. WEST MD
Radiology (Diagnostic Radiology)
2650 RIDGE AVE, DEPARTMENT OF RADIOLOGY, G507
EVANSTON, IL 60201
Cook County (847) 570-2475
JOEL BERNSTEIN M.D.
Radiology (Diagnostic Radiology)
2650 RIDGE AVE, EVANSTON HOSPITAL
EVANSTON, IL 60201
Cook County (847) 570-1206
MATTHEW R. SHERWOOD MD
Internal Medicine
2650 RIDGE AVE, DIVISION OF INTERNAL MEDICINE RM 4324
EVANSTON, IL 60201
Cook County (847) 570-1010
MICHAEL T. GILLAM M.D.
Emergency Medicine
2650 RIDGE AVE, EMERGENCY MEDICINE RM G909
EVANSTON, IL 60201
Cook County (847) 570-2114
MARLENE ANGELICO CNP
Nurse Practitioner (Acute Care)
2650 RIDGE AVE, EMERGENCY MEDICINE, RM G903C
EVANSTON, IL 60201
Cook County (847) 570-1355
MINA KEROLOS MD
Hospitalist
2650 RIDGE AVE
EVANSTON, IL 60201
Cook County (847) 570-1010

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 Timothy Oh's NPI number?

The NPI number for Timothy Oh is 1750840856. It was assigned to this individual provider in the NPPES registry on March 18, 2019.

Where is Timothy Oh located?

Timothy Oh practices at 2650 Ridge Ave, Evanston, IL 60201. The listed phone number is (847) 570-2112.

What is Timothy Oh's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology, with taxonomy code 207RH0000X.

Is Timothy Oh enrolled in Medicare?

Yes. Timothy Oh is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Timothy Oh's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Timothy Oh reassigns Medicare benefits to Endeavor Health Medical Group (Evanston, 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 Timothy Oh's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Timothy Oh accept?

Health plans from Ambetter Health, Ambetter Health of Delaware and Oscar Health list Timothy Oh as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for Timothy Oh was last updated on October 22, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 days 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.