Active NPI
Mark Walter Layton, M.D.
- Rheumatology Physician
- Olympia, WA
National Provider Identifier
1891846077
On this page
Key facts
NPPES NPI Registry- Primary specialty
- Rheumatology Physician
- License
- MD00024518
- Practice address
- 1212 Harrison Ave NW
Olympia, WA 98502-5466 - Phone
- (360) 754-6700
- Fax
- (360) 754-0164
- NPI assigned
- Jan 15, 2007
- Sex
- Male
- Sole proprietor
- No
NPPES NPI Registry
Registry information is reported by the provider to CMS and is not verified. About this source
Specialties & licenses 3
| Specialty (taxonomy) | Code | License | State | Primary |
|---|---|---|---|---|
| Internal Medicine Physician | 207R00000X | MD00024518 | WA | |
| Legal Medicine | 173000000X | MD00024518 | WA | |
| Rheumatology Physician | 207RR0500X | MD00024518 | WA | Primary |
Addresses
Primary practice location
1212 Harrison Ave NW
Olympia, WA 98502-5466
Mailing address
1212 Harrison Ave NW
Olympia, WA 98502-5466
Phone (360) 754-6700
Other identifiers 2
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 12371 | Other | WA | L&I NUMBER |
| 1027689 | Medicaid | WA |
Medicare participation
Medicare enrollment files- Medicare fee-for-service enrollment
- Enrolled in WA
- Eligible to order & refer
- Part B services: Yes
- Medical equipment: Yes
- Home health: Yes
- Power mobility devices: Yes
- Hospice: Yes
Enrollment records 1
Care Compare profile
Medicare Care Compare- Specialty
- Rheumatology
- Education
- University of Washington School of Medicine, 1982
- Medicare assignment
- Accepts the Medicare-approved amount as payment in full
Practice addresses (Care Compare)
1212 Harrison Ave NW
Olympia, WA 98502-5466
Phone (360) 754-6700
Hospital & facility affiliations
- Mason General Hospital & Family of Clinics
- Summit Pacific Medical Center
- Willapa Harbor Hospital
Merit-based Incentive Payment System (MIPS)
- Final score
- 22.95 of 100
- Quality
- 0
- Improvement activities
- 0
- Cost
- 76.5
National Provider Directory
National Provider Directory- Medicare enrollment (NPD)
- Enrolled
- Credentials
- Doctor of Medicine
Practice roles
| Organization | Specialty | Status | New patients |
|---|---|---|---|
| Olympia Arthritis & Rehabilitation Clinic Inc PS | Legal Medicine | Current | Accepting new patients |
Locations
1212 Harrison Ave NW
Olympia, WA 98502
Phone (360) 754-6700
Organizations & group practices 1
Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.
-
- Legal Medicine
- Olympia, WA
- NPI 1952453748
Hospital & facility affiliations 7
Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.
-
- Critical Access Hospital
- Elma, WA
- NPI 1740211028
-
- Critical Access Hospital
- South Bend, WA
- NPI 1295708683
-
- Critical Access Hospital
- Shelton, WA
- NPI 1760568752
-
- Foot & Ankle Surgery Podiatrist
- Shelton, WA
- NPI 1437486248
Hospital
-
- Surgery Physician
- Shelton, WA
- NPI 1639339666
Hospital
-
- Ophthalmologic Surgery Clinic/Center
- Shelton, WA
- NPI 1922196609
Hospital
NPI Registry JSON
The complete NPPES record for this NPI in the NPI Registry API format.
{
"created_epoch": "1168819200000",
"enumeration_type": "NPI-1",
"last_updated_epoch": "1782777600000",
"number": "1891846077",
"addresses": [
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "MAILING",
"address_type": "DOM",
"address_1": "1212 HARRISON AVE NW",
"city": "OLYMPIA",
"state": "WA",
"postal_code": "985025466",
"telephone_number": "360-754-6700",
"fax_number": "360-357-2202"
},
{
"country_code": "US",
"country_name": "United States",
"address_purpose": "LOCATION",
"address_type": "DOM",
"address_1": "1212 HARRISON AVE NW",
"city": "OLYMPIA",
"state": "WA",
"postal_code": "985025466",
"telephone_number": "360-754-6700",
"fax_number": "360-754-0164"
}
],
"practiceLocations": [],
"basic": {
"last_name": "LAYTON",
"first_name": "MARK",
"middle_name": "WALTER",
"name_prefix": "Dr.",
"credential": "M.D.",
"sole_proprietor": "NO",
"sex": "M",
"enumeration_date": "2007-01-15",
"last_updated": "2026-06-30",
"certification_date": "2026-06-30",
"status": "A"
},
"taxonomies": [
{
"code": "207R00000X",
"taxonomy_group": "",
"desc": "Internal Medicine",
"state": "WA",
"license": "MD00024518",
"primary": false
},
{
"code": "173000000X",
"taxonomy_group": "",
"desc": "Legal Medicine",
"state": "WA",
"license": "MD00024518",
"primary": false
},
{
"code": "207RR0500X",
"taxonomy_group": "",
"desc": "Internal Medicine, Rheumatology",
"state": "WA",
"license": "MD00024518",
"primary": true
}
],
"identifiers": [
{
"code": "01",
"desc": "Other (non-Medicare)",
"issuer": "L&I NUMBER",
"identifier": "12371",
"state": "WA"
},
{
"code": "05",
"desc": "MEDICAID",
"issuer": null,
"identifier": "1027689",
"state": "WA"
}
],
"endpoints": [],
"other_names": []
}Other providers in Olympia, WA
Sources for this page
- NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jun 30, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
- Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
- Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
- National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.