WILLIAM TILLIS
NPI 1669468377
Internal Medicine - Pulmonary Disease in Lake Geneva, WI

Q: What is William Tillis's NPI number?

The NPI number for William Tillis is 1669468377. It was assigned to this individual provider in the NPPES registry on September 27, 2005.

Q: What is William Tillis's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Pulmonary Disease, with taxonomy code 207RP1001X.

Q: When was this NPI record last updated?

The NPPES record for William Tillis was last updated on September 14, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.

Active since September 27, 2005PECOS EnrolledAccepts Medicare Assignment

99.32/100

CMS Quality Rating

N2950 STATE ROAD 67, LAKE GENEVA, WI 53147(262) 245-0535(262) 245-2248 Get Directions Write a Review

NPPES record last updated: September 14, 2023. Verified against the NPPES registry weekly; last sync: October 25, 2026.

On this page

About William Tillis NPPES

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

WILLIAM TILLIS (NPI 1669468377) is an individual pulmonary disease provider in Lake Geneva, Wisconsin, licensed in Wisconsin (81911-20) and active in the NPI registry since September 2005. He is enrolled in Medicare PECOS, is affiliated with Mercy Health System Corp, and maintains 4 additional practice locations.

NPPES Registry Identity

NPI1669468377

Entity TypeIndividualMale

Primary Taxonomy207RP1001X

Provider Legal NameWILLIAM TILLIS

Location AddressN2950 STATE ROAD 67Lake Geneva, WI 53147-2655

Mailing AddressN2950 State Road 67Lake Geneva, WI 53147-2655 · (262) 245-0535 · Fax (262) 245-2248

Phone(262) 245-0535

Fax(262) 245-2248

Sole ProprietorNo

Medical School CMSUniversity Of Illinois College Of Med (chi/peor/rock/chm-urb)Graduated 1986

Enumeration DateSeptember 27, 2005

Last NPPES UpdateSeptember 14, 2023

NPPES CertifiedSeptember 14, 2023

✔ NPI 1669468377 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Pulmonary DiseaseAllopathic & Osteopathic Physicians

Taxonomy Code207RP1001X

Licenses✔ Licensed in WI · 81911-20✔ Licensed in SC · 83330✔ Licensed in IL · 036085931

Definition

An internist who treats diseases of the lungs and airways. The pulmonologist diagnoses and treats cancer, pneumonia, pleurisy, asthma, occupational and environmental diseases, bronchitis, sleep disorders, emphysema and other complex disorders of the lungs.

N2950 STATE ROAD 67, Lake Geneva, WI 53147

Open in Google Maps ↗

Secondary Practice Locations 4

Location 11 Richland Medical Park Dr Ste 300Columbia, SC 29203-6831 · Phone (803) 545-5500 · Fax (803) 933-3022

Location 21001 Main St, Suite 200Peoria, IL 61606-1907 · Phone (309) 672-5682 · Fax (309) 672-3147

Location 31000 Mineral Point AveJanesville, WI 53548-2982 · Phone (608) 756-6868 · Fax (608) 756-6289

Location 4903 Mineral Point AveJanesville, WI 53548-2970 · Phone (608) 752-6255 · Fax (608) 752-6253

Other Identifiers 2

Medicaid036085931IL

Medicaid833307SC

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, MercyCare, MercyCare Health Plans.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

William Tillis 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 ID5991765075

PECOS Enrollment IDI20100115000140, I20230913001846

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 William Tillis reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Mercy Health System Corporation

Same address

Critical Access

N2950 STATE ROAD 67
Lake Geneva, WI 53147

Reassigned Medicare billing, Wisconsin and Illinois enrollments
Also billed through NPI 1598718603 (Wisconsin)
271 clinicians in this Medicare group

NPI 1699728550 (262) 245-0535

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 7

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.

67 services53 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.

61 services46 patients

Test to measure expiratory airflow and volume changes before and after medication administration 94060

This procedure measures how air flows in and out of your lungs. It's done before and after medication to see if the treatment improves your breathing. It's a simple, non-invasive test that involves breathing into a device called a spirometer.

59 services58 patients

Test to examine how well the lungs exchange gases 94729

This is a test called a pulmonary function test, which helps understand the efficiency of your lungs. It measures how much air your lungs can hold, how quickly you can move air in and out of your lungs, and how well your lungs put oxygen into and remove carbon dioxide from your blood.

53 services52 patients

Test to determine lung volumes using sensors 94726

This test, called spirometry, measures lung capacity using sensors. You breathe into a mouthpiece attached to a device that records the amount and rate of air you inhale and exhale. It helps diagnose and monitor lung conditions.

49 services49 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

48 services48 patients

Hospital Affiliations CMS Care Compare 2

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

Mercy Health System Corp

Acute Care Hospitals · Janesville, WI

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number520066

Location1000 Mineral Point AveJanesville, WI 53548 · Rock County

Emergency services Birthing friendly

Mercy Walworth Hospital & Medical Center

Critical Access Hospitals · Lake Geneva, WI

5/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number521357

LocationN2950 State Road 67Lake Geneva, WI 53147 · Walworth County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 53147 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

$123.69 typical visit price

range $53.90 – $163.24

Typical copayment $30.92 (range $13.47 – $40.81)

Most-billed visit code 99204

Established Patient

$95.41 typical visit price

range $17.40 – $133.76

Typical copayment $23.85 (range $4.35 – $33.44)

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.

99.32/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored through an Alternative Payment Model

Quality

90.59

Promoting Interoperability

100

Improvement Activities

Referred Medical Equipment & Supplies CMS DME claims 5

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

Portable gaseous oxygen system, rental; includes portable container, regulator, flowmeter, humidifier, cannula or mask, and tubing E0431

DME-Oxygen and Supplies · category DC000N

1 supplier12 claims12 services$11.62 avg. paid by Medicare

Home ventilator, any type, used with invasive interface, (e.g., tracheostomy tube) E0465

DME-Other DME · category DE005N

1 supplier12 claims23 services$922.87 avg. paid by Medicare

Cough stimulating device, alternating positive and negative airway pressure E0482

DME-Other DME · category DE000N

2 suppliers17 claims17 services$324.03 avg. paid by Medicare

Nebulizer, with compressor E0570

DME-Other DME · category DE000N

1 supplier19 claims25 services$3.52 avg. paid by Medicare

Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390

DME-Oxygen and Supplies · category DC002N

1 supplier12 claims12 services$49.76 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 20

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

JULIE A RICE LPC

Counselor (Professional)