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KAREN O'MARA D.O.
NPI 1235112269
Internal Medicine - Critical Care Medicine in Oak Lawn, IL

Active since November 23, 2005PECOS Enrolled
9555 S 52ND AVE, OAK LAWN, IL 60453(708) 684-6867(708) 684-6869 Get Directions Write a Review

NPPES record last updated: June 18, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jun 18, 2025, Jul 11, 2022 (2 updates tracked since 2022).

About Karen O'mara D.o. NPPES

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

KAREN O'MARA D.O. (NPI 1235112269) is an individual critical care medicine provider in Oak Lawn, Illinois, licensed in Illinois (036-057006) and active in the NPI registry since November 2005. She is enrolled in Medicare PECOS and maintains a secondary practice location in Evergreen Park.

NPPES Registry Identity

NPI1235112269
Entity TypeIndividualFemale
Primary Taxonomy207RC0200X
Provider Legal NameKAREN O'MARACredential: D.O.
Location Address9555 S 52ND AVEOak Lawn, IL 60453-3054
Mailing Address29373 Network PlChicago, IL 60673-1293 · (847) 390-5900
Phone(708) 684-6867
Fax(708) 684-6869
Sole ProprietorNo
Enumeration DateNovember 23, 2005
Last NPPES UpdateJune 18, 20252 updates tracked since enumeration
NPPES CertifiedJune 18, 2025
✔ NPI 1235112269 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Critical Care MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207RC0200X
Licenses✔ Licensed in IL · 036-057006✔ Licensed in KS · 05-43634
Definition
An internist who diagnoses, treats and supports patients with multiple organ dysfunction. This specialist may have administrative responsibilities for intensive care units and may also facilitate and coordinate patient care among the primary physician, the critical care staff and other specialists.
Also ListedEmergency Medicine · Emergency Medical ServicesTaxonomy 207PE0004X · License 036057006 (IL)
9555 S 52ND AVE, Oak Lawn, IL 60453
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Secondary Practice Location 1

Location 12800 W 95th StEvergreen Park, IL 60805 · Phone (708) 422-4221 · Fax (708) 422-4415

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Karen O'mara D.o. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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

2

Medicare enrollment records show Karen O'mara reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Aurora Medical Group, Inc.
89 mi
Nurse Anesthetist, Certified Registered
3301 W FOREST HOME AVE
Milwaukee, WI 53215
  • Reassigned Medicare billing, Wisconsin enrollment
  • 4,609 clinicians in this Medicare group
NPI 1427271378 (877) 576-3544
Ascension NE Wisconsin, Inc
164 mi
General Acute Care Hospital
500 S OAKWOOD RD
Oshkosh, WI 54904
  • Reassigned Medicare billing, Wisconsin enrollment
  • 194 clinicians in this Medicare group
NPI 1912527193 (920) 223-2000

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 60453 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
$138.86 typical visit price
range $60.08 – $183.39
Typical copayment $34.71 (range $15.02 – $45.84)
Most-billed visit code 99204
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.

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.

ELIZABETH M PAYMENT MD
Family Medicine
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 634-0950
DR. DOBROSLAV DOBRIKOV DO
Family Medicine
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 422-5700
BHARATI PRASAD M.D.
Internal Medicine (Critical Care Medicine)
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 684-6867
LORENA GUZMAN-SCHMITT APRN
Nurse Practitioner (Family)
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 684-5437
GURANKIT SINGH DO
Family Medicine
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 422-5700
ERIKA VILLANUEVA
Dietitian, Registered
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 634-0950
DR. VASANTHA SAMALA M.D.
Internal Medicine (Critical Care Medicine)
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 634-0950
KELLY N BILLINGSLEY NP
Nurse Practitioner (Family)
9555 S 52ND AVE
OAK LAWN, IL 60453
Cook County (708) 634-0950

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 Karen O'mara's NPI number?

The NPI number for Karen O'mara is 1235112269. It was assigned to this individual provider in the NPPES registry on November 23, 2005.

Where is Karen O'mara located?

Karen O'mara practices at 9555 S 52nd Ave, Oak Lawn, IL 60453. The listed phone number is (708) 684-6867.

What is Karen O'mara's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.

Is Karen O'mara enrolled in Medicare?

Yes. Karen O'mara is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Karen O'mara's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Karen O'mara reassigns Medicare benefits to 2 organizations: Aurora Medical Group, Inc. (Milwaukee, WI) and Ascension NE Wisconsin, Inc (Oshkosh, WI). 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 Karen O'mara'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 Karen O'mara was last updated on June 18, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 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.