1. Home
  2. Directory
  3. Illinois
  4. Libertyville
  5. Internal Medicine
  6. NPI Profile

MR. MARIUSZ MILEJCZYK MD
NPI 1467598235
Internal Medicine in Libertyville, IL

Active since January 29, 2007PECOS EnrolledAccepts Medicare Assignment
58.35/100
CMS Quality Rating
1880 W WINCHESTER RD STE 106, LIBERTYVILLE, IL 60048(847) 367-4277(847) 810-0287 Get Directions Write a Review

NPPES record last updated: December 27, 2024. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Dec 27, 2024, Dec 19, 2024 (2 updates tracked since 2024).

About Mr. Mariusz Milejczyk Md NPPES

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

MR. MARIUSZ MILEJCZYK MD (NPI 1467598235) is an individual internal medicine provider in Libertyville, Illinois, licensed in Illinois (036093940) and active in the NPI registry since January 2007. He is enrolled in Medicare PECOS, is affiliated with Northshore University Healthsystem - Evanston Hospital, and is a graduate of Other (1990).

NPPES Registry Identity

NPI1467598235
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameMR. MARIUSZ MILEJCZYKCredential: MD
Location Address1880 W WINCHESTER RD STE 106Libertyville, IL 60048-5321
Mailing Address15 Tower Crt 255Gurnee, IL 60031 · (847) 623-8818 · Fax (847) 625-8059
Phone(847) 367-4277
Fax(847) 810-0287
Sole ProprietorNo
Medical School CMSOtherGraduated 1990
Enumeration DateJanuary 29, 2007
Last NPPES UpdateDecember 27, 20242 updates tracked since enumeration
NPPES CertifiedDecember 27, 2024
✔ NPI 1467598235 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in IL · 036093940
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
1880 W WINCHESTER RD STE 106, Libertyville, IL 60048
Open in Google Maps ↗

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include 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 and accepts Medicare assignment

Mr. Mariusz Milejczyk Md 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 ID840399788
PECOS Enrollment IDI20070619000177
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 Mariusz Milejczyk reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Lake County Internal Medicine Associates, LLC
6.3 mi
Internal Medicine
5911 KILDEER CT
Long Grove, IL 60047
  • Reassigned Medicare billing, Illinois enrollment
NPI 1154686525 (847) 478-5108

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 9

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.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
658 services140 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
118 services66 patients
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439
An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.
79 services79 patients
Transitional care management services for problem of high complexity 99496
Transitional care management services are designed to ensure a smooth transition from a hospital to home or another care setting for patients with complex health issues. These services include medication management, patient education, and coordination with healthcare providers.
53 services32 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
23 services20 patients
Annual alcohol misuse screening, 5 to 15 minutes G0442
An annual alcohol misuse screening is a 15-minute check-up to assess your drinking habits. It helps identify if you're consuming alcohol in a way that could harm your health. This is not a judgment, but a tool to promote your wellbeing.
19 services19 patients

Hospital Affiliations CMS Care Compare 4

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

Northshore University Healthsystem - Evanston Hospital

Acute Care Hospitals · Evanston, IL
5/5 CMS rating
OwnershipVoluntary non-profit - Other
CMS Certification Number140010
Location2650 Ridge AveEvanston, IL 60201 · Cook County
Emergency services Birthing friendly

Vista Medical Center East

Acute Care Hospitals · Waukegan, IL
2/5 CMS rating
OwnershipProprietary
CMS Certification Number140084
Location1324 North Sheridan RoadWaukegan, IL 60085 · Lake County
Emergency services Birthing friendly

Northwestern Lake Forest Hospital

Acute Care Hospitals · Lake Forest, IL
5/5 CMS rating
OwnershipVoluntary non-profit - Other
CMS Certification Number140130
Location1000 N Westmoreland RoadLake Forest, IL 60045 · Lake County
Emergency services Birthing friendly

Advocate Condell Medical Center

Acute Care Hospitals · Libertyville, IL
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number140202
Location801 S Milwaukee AveLibertyville, IL 60048 · Lake County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 60048 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
$137.43 typical visit price
range $59.81 – $181.38
Typical copayment $34.35 (range $14.95 – $45.34)
Most-billed visit code 99204
Established Patient
$105.07 typical visit price
range $19.15 – $147.12
Typical copayment $26.26 (range $4.78 – $36.78)
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.

58.35/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Individually scored
Quality87.67
Promoting Interoperability21
Improvement Activities40
Cost39.35

Reported Quality Measures

Documentation of Current Medications in the Medical Record
99%2,339 patients4/55-star benchmark: 100%
e-Prescribing
99%9,714 patients4/55-star benchmark: 100%
Falls: Screening for Future Fall Risk
95%163 patients4/55-star benchmark: 100%
Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan
74%362 patients4/55-star benchmark: 98%
Preventive Care and Screening: Screening for Depression and Follow-Up Plan
98%328 patients5/55-star benchmark: 97%
Preventive Care and Screening: Tobacco Use: Screening and Cessation Intervention
Patients combinedPopulations: 97% · 333 patients
Patients screened: 98% · 333 patients
88%26 patients4/55-star benchmark: 100%
Provide Patients Electronic Access to Their Health Information
0%367 patients1/55-star benchmark: 100%
Use of High-Risk Medications in Older Adults
Lower rates are better for this measure.
Patients appropriateDiagnosis: 19% · 173 patients
Patients totalRate: 28% · 173 patients
27%173 patients2/55-star benchmark: 100%
Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Referred Medical Equipment & Supplies CMS DME claims 7

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Blood glucose test or reagent strips for home blood glucose monitor, per 50 strips A4253
DME-Other DME · category DE017N
8 suppliers22 claims68 services$6.61 avg. paid by Medicare
Nebulizer, with compressor E0570
DME-Other DME · category DE000N
2 suppliers11 claims11 services$3.78 avg. paid by Medicare
Standard wheelchair K0001
DME-Wheelchairs · category DD000N
3 suppliers17 claims17 services$15.02 avg. paid by Medicare
Standard hemi (low seat) wheelchair K0002
DME-Wheelchairs · category DD000N
2 suppliers18 claims18 services$27.43 avg. paid by Medicare
Lightweight wheelchair K0003
DME-Wheelchairs · category DD000N
3 suppliers21 claims21 services$28.64 avg. paid by Medicare
Elevating leg rests, pair (for use with capped rental wheelchair base) K0195
DME-Wheelchairs · category DD021N
4 suppliers22 claims22 services$7.86 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 2

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

LAKE COUNTY ASSOCIATE OF INTERNAL MEDICINE , LLC
Internal Medicine
1880 W WINCHESTER RD STE 106
LIBERTYVILLE, IL 60048
Lake County (847) 367-8297
ADVANCED PERITONEAL DIALYSIS CENTER
Internal Medicine (Nephrology)
1880 W WINCHESTER RD STE 106
LIBERTYVILLE, IL 60048
Lake County (847) 247-1010

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 Mariusz Milejczyk's NPI number?

The NPI number for Mariusz Milejczyk is 1467598235. It was assigned to this individual provider in the NPPES registry on January 29, 2007.

Where is Mariusz Milejczyk located?

Mariusz Milejczyk practices at 1880 W Winchester Rd Ste 106, Libertyville, IL 60048. The listed phone number is (847) 367-4277.

What is Mariusz Milejczyk's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Mariusz Milejczyk enrolled in Medicare?

Yes. Mariusz Milejczyk 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 organization bills Medicare for Mariusz Milejczyk's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mariusz Milejczyk reassigns Medicare benefits to Lake County Internal Medicine Associates, LLC (Long Grove, 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 Mariusz Milejczyk's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Mariusz Milejczyk accept?

Health plans from Oscar Health list Mariusz Milejczyk 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.

Is Mariusz Milejczyk affiliated with any hospitals?

According to CMS data, Mariusz Milejczyk is affiliated with Northshore University Healthsystem - Evanston Hospital, Vista Medical Center East, Northwestern Lake Forest Hospital and Advocate Condell Medical Center.

When was this NPI record last updated?

The NPPES record for Mariusz Milejczyk was last updated on December 27, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 21 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.