MARGARET MASS MD
NPI 1083343107
Family Medicine in Everett, WA
About Margaret Mass Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARGARET MASS MD (NPI 1083343107) is an individual family medicine provider in Everett, Washington, licensed in Washington (MD70026676) and active in the NPI registry since June 2022. She is enrolled in Medicare PECOS and is a graduate of University Of Illinois College Of Med (chi/peor/rock/chm-urb) (2022).
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
Margaret Mass 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 Margaret Mass reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Everett, WA 98201
- Reassigned Medicare billing, Washington enrollment
- 1,285 clinicians in this Medicare group
Seattle, WA 98122
- Reassigned Medicare billing, Washington enrollment
- 911 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 98201 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.
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 Margaret Mass's NPI number?
The NPI number for Margaret Mass is 1083343107. It was assigned to this individual provider in the NPPES registry on June 6, 2022.
Where is Margaret Mass located?
Margaret Mass practices at 3901 Hoyt Ave, Everett, WA 98201. The listed phone number is (425) 303-3091.
What is Margaret Mass's specialty?
The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.
Is Margaret Mass enrolled in Medicare?
Yes. Margaret Mass 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 Margaret Mass's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Margaret Mass reassigns Medicare benefits to 2 organizations: Optum Care Washington PLLC (Everett, WA) and The Polyclinic PLLC (Seattle, WA). 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 Margaret Mass's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Margaret Mass accept?
Health plans from Premera Blue Cross Blue Shield of Alaska and Providence Health Plan list Margaret Mass 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.
When was this NPI record last updated?
The NPPES record for Margaret Mass was last updated on July 20, 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.
# Margaret Mass, MD · NPI 1083343107
Family Medicine physician in Everett, Washington. Individual provider, active in the CMS NPPES registry since June 6, 2022.
## Identity
- **NPI:** 1083343107 (Entity type: Individual)
- **Enumerated:** June 6, 2022
- **Primary specialty:** Family Medicine · taxonomy 207Q00000X
- **State license:** MD70026676 (Washington)
- **Sole proprietor:** No
## Practice location
- **Address:** 3901 HOYT AVE, Everett, WA 98201-4918
- **Phone:** (425) 303-3091
## 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:** 2 organizations under Medicare reassignment (form CMS-855R): Optum Care Washington PLLC (NPI 1831186766, Everett, WA); The Polyclinic PLLC (NPI 1174594634, Seattle, WA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Illinois College Of Med, class of 2022
## Record status
- **NPPES last updated:** July 20, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1083343107) · Data from the CMS NPPES public registry.