DR. MARK WALTER LAYTON M.D.
NPI 1891846077
Internal Medicine - Rheumatology in Olympia, WA
About Dr. Mark Walter Layton M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. MARK WALTER LAYTON M.D. (NPI 1891846077) is an individual rheumatology provider in Olympia, Washington, licensed in Washington (MD00024518) and active in the NPI registry since January 2007. He is enrolled in Medicare PECOS, is affiliated with Willapa Harbor Hospital, and is a graduate of University Of Washington School Of Medicine (1982).
NPPES Registry Identity
Specialties & Licenses 3
Other Identifiers 2
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. Mark Walter Layton M.d. 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 Reassignment
Medicare enrollment records show Mark Layton reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Olympia, WA 98502
- Reassigned Medicare billing, Washington enrollment
- 2 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 2
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.
Willapa Harbor Hospital
Critical Access Hospitals · South Bend, WASummit Pacific Medical Center
Critical Access Hospitals · Elma, WAMason General Hospital & Family Of Clinics
Critical Access Hospitals · Shelton, WAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 98502 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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.
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.
OLYMPIA, WA 98502
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 Layton's NPI number?
The NPI number for Mark Layton is 1891846077. It was assigned to this individual provider in the NPPES registry on January 15, 2007.
Where is Mark Layton located?
Mark Layton practices at 1212 Harrison Ave NW, Olympia, WA 98502. The listed phone number is (360) 754-6700.
What is Mark Layton's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Rheumatology, with taxonomy code 207RR0500X.
Is Mark Layton enrolled in Medicare?
Yes. Mark Layton 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 Mark Layton's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Mark Layton reassigns Medicare benefits to Olympia Arthritis & Rehabilitation Clinic Inc Ps (Olympia, WA). 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 Mark Layton's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Mark Layton accept?
Health plans from Ambetter Health, Premera Blue Cross Blue Shield of Alaska and Providence Health Plan list Mark Layton 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 Mark Layton affiliated with any hospitals?
According to CMS data, Mark Layton is affiliated with Willapa Harbor Hospital, Summit Pacific Medical Center and Mason General Hospital & Family Of Clinics.
When was this NPI record last updated?
The NPPES record for Mark Layton was last updated on June 30, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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. Mark Walter Layton, M.D. · NPI 1891846077
Rheumatology physician in Olympia, Washington. Individual provider, active in the CMS NPPES registry since January 15, 2007.
## Identity
- **NPI:** 1891846077 (Entity type: Individual)
- **Enumerated:** January 15, 2007
- **Primary specialty:** Internal Medicine - Rheumatology · taxonomy 207RR0500X
- **State license:** MD00024518 (Washington)
- **Sole proprietor:** No
## Practice location
- **Address:** 1212 HARRISON AVE NW, Olympia, WA 98502-5466
- **Phone:** (360) 754-6700 · **Fax:** (360) 754-0164
## 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:** Olympia Arthritis & Rehabilitation Clinic Inc Ps (NPI 1952453748, Olympia, WA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Washington School Of Medicine, class of 1982
## Record status
- **NPPES last updated:** June 30, 2026
- **Other identifiers:** Other 12371 (WA); Medicaid 1027689 (WA)
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Source: [NPI Profile](https://npiprofile.com/npi/1891846077) · Data from the CMS NPPES public registry.