DR. WILLIS KO MD
NPI 1215465307
Internal Medicine - Interventional Cardiology in Maryville, IL
About Dr. Willis Ko Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. WILLIS KO MD (NPI 1215465307) is an individual interventional cardiology provider in Maryville, Illinois, licensed in Illinois (036171090) and active in the NPI registry since June 2017. He is enrolled in Medicare PECOS, is affiliated with Anderson Hospital, and maintains 3 additional practice locations.
NPPES Registry Identity
Specialties & Licenses 3
Secondary Practice Locations 3
Accepted 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
Dr. Willis Ko 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.
Medicare Billing Reassignments
2Medicare enrollment records show Willis Ko reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Saint Louis, MO 63141
- Reassigned Medicare billing, Illinois and Missouri enrollments
- Also billed through NPI 1679503668 (Missouri)
- 507 clinicians in this Medicare group
Fenton, MO 63026
- Reassigned Medicare billing, Missouri enrollment
- 697 clinicians in this Medicare group
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 8
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.
Hospital Affiliations CMS Care Compare 3
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Anderson Hospital
Acute Care Hospitals · Maryville, ILSsm St Clare Health Center
Acute Care Hospitals · Fenton, MOChristian Hospital Northeast
Acute Care Hospitals · Saint Louis, MOPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 62062 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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 Willis Ko's NPI number?
The NPI number for Willis Ko is 1215465307. It was assigned to this individual provider in the NPPES registry on June 1, 2017.
Where is Willis Ko located?
Willis Ko practices at 6810 State Route 162 Ste 102B, Maryville, IL 62062. The listed phone number is (618) 288-4076.
What is Willis Ko's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Interventional Cardiology, with taxonomy code 207RI0011X.
Is Willis Ko enrolled in Medicare?
Yes. Willis Ko 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 Willis Ko's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Willis Ko reassigns Medicare benefits to 2 organizations: Fairview Heights Medical Group, Sc (Saint Louis, MO) and Ssm Medical Group, Inc. (Fenton, MO). 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 Willis Ko's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Willis Ko accept?
Health plans from Anthem Blue Cross and Blue Shield, Medica and Oscar Insurance Company list Willis Ko 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 Willis Ko affiliated with any hospitals?
According to CMS data, Willis Ko is affiliated with Anderson Hospital, Ssm St Clare Health Center and Christian Hospital Northeast.
When was this NPI record last updated?
The NPPES record for Willis Ko was last updated on September 19, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 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.
# Dr. Willis Ko, MD · NPI 1215465307
Interventional Cardiology physician in Maryville, Illinois. Individual provider, active in the CMS NPPES registry since June 1, 2017.
## Identity
- **NPI:** 1215465307 (Entity type: Individual)
- **Enumerated:** June 1, 2017
- **Primary specialty:** Internal Medicine - Interventional Cardiology · taxonomy 207RI0011X
- **State license:** 036171090 (Illinois)
- **Sole proprietor:** No
## Practice location
- **Address:** 6810 STATE ROUTE 162 STE 102B, Maryville, IL 62062-8560
- **Phone:** (618) 288-4076 · **Fax:** (618) 288-4215
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): Fairview Heights Medical Group, Sc (NPI 1811392210, Saint Louis, MO); Ssm Medical Group, Inc. (NPI 1700966207, Fenton, MO) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2017
## Record status
- **NPPES last updated:** September 19, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1215465307) · Data from the CMS NPPES public registry.