MARK GORTON WILLS MD
NPI 1063525715
Emergency Medicine in Sonoma, CA
About Mark Gorton Wills Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARK GORTON WILLS MD (NPI 1063525715) is an individual emergency medicine provider in Sonoma, California, licensed in California (G63295) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 4
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Mark Gorton Wills Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show Mark Wills reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
San Francisco, CA 94109
- Reassigned Medicare billing, California enrollment
- 155 clinicians in this Medicare group
Hollister, CA 95023
- Reassigned Medicare billing, California enrollment
- 38 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 95476 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 4
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
SONOMA, CA 95476
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 Mark Wills's NPI number?
The NPI number for Mark Wills is 1063525715. It was assigned to this individual provider in the NPPES registry on August 16, 2006.
Where is Mark Wills located?
Mark Wills practices at 347 Andrieux Street, Sonoma, CA 95476. The listed phone number is (707) 935-5100.
What is Mark Wills's specialty?
The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.
Is Mark Wills enrolled in Medicare?
Yes. Mark Wills is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Mark Wills's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Wills reassigns Medicare benefits to 2 organizations: San Francisco Emergency Medical Associates (San Francisco, CA) and Big River Emergency Physicians Inc (Hollister, CA). 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 Mark Wills'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 Mark Wills was last updated on July 7, 2008. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.
# Mark Gorton Wills, MD · NPI 1063525715
Emergency Medicine physician in Sonoma, California. Individual provider, active in the CMS NPPES registry since August 16, 2006.
## Identity
- **NPI:** 1063525715 (Entity type: Individual)
- **Enumerated:** August 16, 2006
- **Primary specialty:** Emergency Medicine · taxonomy 207P00000X
- **State license:** G63295 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 347 ANDRIEUX STREET, Sonoma, CA 95476-6811
- **Phone:** (707) 935-5100
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for durable medical equipment, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): San Francisco Emergency Medical Associates (NPI 1134110661, San Francisco, CA); Big River Emergency Physicians Inc (NPI 1033501168, Hollister, CA) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** July 7, 2008
- **Other identifiers:** Medicare UPIN D44647 (CA); Medicaid 00G632950 (CA); Medicare PIN 00G632955 (CA); and 1 more
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Source: [NPI Profile](https://npiprofile.com/npi/1063525715) · Data from the CMS NPPES public registry.