DR. ROSS MICHAEL ONDERSMA MD
NPI 1841403110
Radiology - Diagnostic Radiology in Lynnwood, WA
About Dr. Ross Michael Ondersma Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. ROSS MICHAEL ONDERSMA MD (NPI 1841403110) is an individual diagnostic radiology provider in Lynnwood, Washington, licensed in Washington (MD60292915) and active in the NPI registry since May 2007. He is enrolled in Medicare PECOS, is affiliated with Swedish Edmonds Hospital, and maintains 2 additional practice locations.
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Locations 2
Other Identifiers 1
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. Ross Michael Ondersma 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
20Medicare enrollment records show Ross Ondersma reassigns Medicare billing to 20 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Lynnwood, WA 98036
- Reassigned Medicare billing, Washington enrollment
- 209 clinicians in this Medicare group
Edmonds, WA 98026
- Reassigned Medicare billing, Washington enrollment
- 200 clinicians in this Medicare group
Everett, WA 98208
- Reassigned Medicare billing, Washington enrollment
- 194 clinicians in this Medicare group
Kirkland, WA 98034
- Reassigned Medicare billing, Washington enrollment
- 196 clinicians in this Medicare group
Seattle, WA 98101
- Reassigned Medicare billing, Washington enrollment
- 663 clinicians in this Medicare group
Seattle, WA 98104
- Reassigned Medicare billing, Washington enrollment
- 129 clinicians in this Medicare group
Seattle, WA 98104
- Reassigned Medicare billing, Washington enrollment
- 204 clinicians in this Medicare group
Seattle, WA 98104
- Reassigned Medicare billing, Washington enrollment
- 18 clinicians in this Medicare group
Snoqualmie, WA 98065
- Reassigned Medicare billing, Washington enrollment
- Also billed through NPI 1902846546 (Washington), NPI 1144432634 (Washington)
- 17 clinicians in this Medicare group
Olympia, WA 98506
- Reassigned Medicare billing, Washington enrollment
- 186 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 37
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 4
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Swedish Edmonds Hospital
Acute Care Hospitals · Edmonds, WASwedish Medical Center
Acute Care Hospitals · Seattle, WAOlympic Medical Center
Acute Care Hospitals · Port Angeles, WASwedish Issaquah
Acute Care Hospitals · Issaquah, WAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 98036 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.
Reported Quality Measures
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.
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
LYNNWOOD, WA 98036
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 Ross Ondersma's NPI number?
The NPI number for Ross Ondersma is 1841403110. It was assigned to this individual provider in the NPPES registry on May 7, 2007.
Where is Ross Ondersma located?
Ross Ondersma practices at 19020 33rd Ave W Ste 210, Lynnwood, WA 98036. The listed phone number is (425) 563-1500.
What is Ross Ondersma's specialty?
The primary specialty registered for this NPI is Radiology, specializing in Diagnostic Radiology, with taxonomy code 2085R0202X.
Is Ross Ondersma enrolled in Medicare?
Yes. Ross Ondersma 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 Ross Ondersma's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ross Ondersma reassigns Medicare benefits to 20 organizations: Radia Inc P S (Lynnwood, WA), Swedish Radia Imaging Center At Edmonds LLC (Edmonds, WA), Swedish Health Services (Everett, WA), Evergreen Radia LLC (Kirkland, WA), Swedish Health Services (Seattle, WA) and 15 more organizations, listed in the Medicare section above. 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 Ross Ondersma's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Ross Ondersma accept?
Health plans from Arkansas Blue Cross and Blue Shield, Health Advantage, Octave and Premera Blue Cross Blue Shield of Alaska list Ross Ondersma 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 Ross Ondersma affiliated with any hospitals?
According to CMS data, Ross Ondersma is affiliated with Swedish Edmonds Hospital, Swedish Medical Center, Olympic Medical Center and Swedish Issaquah.
When was this NPI record last updated?
The NPPES record for Ross Ondersma was last updated on February 23, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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. Ross Michael Ondersma, MD · NPI 1841403110
Diagnostic Radiology physician in Lynnwood, Washington. Individual provider, active in the CMS NPPES registry since May 7, 2007.
## Identity
- **NPI:** 1841403110 (Entity type: Individual)
- **Enumerated:** May 7, 2007
- **Primary specialty:** Radiology - Diagnostic Radiology · taxonomy 2085R0202X
- **State license:** MD60292915 (Washington)
- **Sole proprietor:** No
## Practice location
- **Address:** 19020 33RD AVE W STE 210, Lynnwood, WA 98036-4748
- **Phone:** (425) 563-1500 · **Fax:** (425) 563-1501
## 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:** 20 organizations under Medicare reassignment (form CMS-855R): Radia Inc P S (NPI 1700045572, Lynnwood, WA); Swedish Radia Imaging Center At Edmonds LLC (NPI 1164494373, Edmonds, WA); Swedish Health Services (NPI 1114356904, Everett, WA); Evergreen Radia LLC (NPI 1922095694, Kirkland, WA); Swedish Health Services (NPI 1073553947, Seattle, WA); and 15 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2006
## Record status
- **NPPES last updated:** February 23, 2026
- **Other identifiers:** Medicaid 2022790 (WA)
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Source: [NPI Profile](https://npiprofile.com/npi/1841403110) · Data from the CMS NPPES public registry.