DR. CLARK L WILLIAMS MD
NPI 1710911417
Emergency Medicine in Lancaster, WI
About Dr. Clark L Williams Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. CLARK L WILLIAMS MD (NPI 1710911417) is an individual emergency medicine provider in Lancaster, Wisconsin, licensed in Wisconsin (42618) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS, is affiliated with Finley Hospital, and is a graduate of University Of Wisconsin School Of Medicine (1999).
NPPES Registry Identity
Specialties & Licenses
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. Clark L Williams 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
4Medicare enrollment records show Clark Williams reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Lancaster, WI 53813
- Reassigned Medicare billing, Wisconsin enrollment
- 53 clinicians in this Medicare group
Dubuque, IA 52001
- Reassigned Medicare billing, Iowa enrollment
- 177 clinicians in this Medicare group
Elkader, IA 52043
- Reassigned Medicare billing, Iowa enrollment
- Also billed through NPI 1184645434 (Iowa)
- 51 clinicians in this Medicare group
Sioux Rapids, IA 50585
- Reassigned Medicare billing, Iowa enrollment
- 176 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
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.
Finley Hospital
Acute Care Hospitals · Dubuque, IAMercyone Elkader Medical Center
Critical Access Hospitals · Elkader, IAGrant Regional Health Center
Critical Access Hospitals · Lancaster, WIPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 53813 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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.
LANCASTER, WI 53813
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 Clark Williams's NPI number?
The NPI number for Clark Williams is 1710911417. It was assigned to this individual provider in the NPPES registry on July 10, 2006.
Where is Clark Williams located?
Clark Williams practices at 507 S Monroe St, Lancaster, WI 53813. The listed phone number is (608) 723-2143.
What is Clark Williams's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Clark Williams enrolled in Medicare?
Yes. Clark Williams 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 Clark Williams's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Clark Williams reassigns Medicare benefits to 4 organizations: Grant Regional Health Center, Inc. (Lancaster, WI), The Finley Hospital (Dubuque, IA), Central Community Hospital (Elkader, IA) and Spencer Municipal Hospital (Sioux Rapids, IA). 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 Clark Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Clark Williams accept?
Health plans from Group Health Cooperative-SCW and Wellmark Health Plan of Iowa, Inc. list Clark Williams 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 Clark Williams affiliated with any hospitals?
According to CMS data, Clark Williams is affiliated with Finley Hospital, Mercyone Elkader Medical Center and Grant Regional Health Center.
When was this NPI record last updated?
The NPPES record for Clark Williams was last updated on September 3, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.
# Dr. Clark L Williams, MD · NPI 1710911417
Emergency Medicine physician in Lancaster, Wisconsin. Individual provider, active in the CMS NPPES registry since July 10, 2006.
## Identity
- **NPI:** 1710911417 (Entity type: Individual)
- **Enumerated:** July 10, 2006
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** 42618 (Wisconsin)
- **Sole proprietor:** No
## Practice location
- **Address:** 507 S MONROE ST, Lancaster, WI 53813-2054
- **Phone:** (608) 723-2143
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 4 organizations under Medicare reassignment (form CMS-855R): Grant Regional Health Center, Inc. (NPI 1255339867, Lancaster, WI); The Finley Hospital (NPI 1073560462, Dubuque, IA); Central Community Hospital (NPI 1952986010, Elkader, IA); Spencer Municipal Hospital (NPI 1275723934, Sioux Rapids, IA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Wisconsin School Of Medicine, class of 1999
## Record status
- **NPPES last updated:** September 3, 2024
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Source: [NPI Profile](https://npiprofile.com/npi/1710911417) · Data from the CMS NPPES public registry.