RAY MUN KOO
NPI 1942166327
Internal Medicine - Hematology & Oncology in Seattle, WA
About Ray Mun Koo NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
RAY MUN KOO (NPI 1942166327) is an individual hematology & oncology provider in Seattle, Washington, licensed in Washington (TR70062707) and active in the NPI registry since December 2025. The provider is enrolled in Medicare PECOS, is affiliated with University Of Washington Medical Ctr, and is a graduate of Other (2012).
NPPES Registry Identity
Specialties & Licenses 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
Ray Mun Koo 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 Ray Mun Koo reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Seattle, WA 98104
- Reassigned Medicare billing, Washington enrollment
- 4,364 clinicians in this Medicare group
Seattle, WA 98195
- Reassigned Medicare billing, Washington enrollment
- 274 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.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
University Of Washington Medical Ctr
Acute Care Hospitals · Seattle, WAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 98109 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.
SEATTLE, WA 98109
SEATTLE, WA 98109
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 Ray Mun Koo's NPI number?
The NPI number for Ray Mun Koo is 1942166327. It was assigned to this individual provider in the NPPES registry on December 30, 2025.
Where is Ray Mun Koo located?
Ray Mun Koo practices at 825 Eastlake Ave E, Seattle, WA 98109. The listed phone number is (206) 520-5000.
What is Ray Mun Koo's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology & Oncology, with taxonomy code 207RH0003X.
Is Ray Mun Koo enrolled in Medicare?
Yes. Ray Mun Koo 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 Ray Mun Koo's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ray Mun Koo reassigns Medicare benefits to 2 organizations: The Association Of University Physicians (Seattle, WA) and University Of Washington (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 Ray Mun Koo's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Ray Mun Koo accept?
Health plans from Premera Blue Cross Blue Shield of Alaska and Providence Health Plan list Ray Mun Koo 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 Ray Mun Koo affiliated with any hospitals?
According to CMS data, Ray Mun Koo is affiliated with University Of Washington Medical Ctr.
When was this NPI record last updated?
The NPPES record for Ray Mun Koo was last updated on December 30, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 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.
# Ray Mun Koo · NPI 1942166327
Hematology & Oncology physician in Seattle, Washington. Individual provider, active in the CMS NPPES registry since December 30, 2025.
## Identity
- **NPI:** 1942166327 (Entity type: Individual)
- **Enumerated:** December 30, 2025
- **Primary specialty:** Internal Medicine - Hematology & Oncology · taxonomy 207RH0003X
- **State license:** TR70062707 (Washington)
- **Sole proprietor:** No
## Practice location
- **Address:** 825 EASTLAKE AVE E, Seattle, WA 98109-4405
- **Phone:** (206) 520-5000
## 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): The Association Of University Physicians (NPI 1023041159, Seattle, WA); University Of Washington (NPI 1326002049, Seattle, WA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2012
## Record status
- **NPPES last updated:** December 30, 2025
---
Source: [NPI Profile](https://npiprofile.com/npi/1942166327) · Data from the CMS NPPES public registry.