ISAAC S. DREYFUS MD
NPI 1104389923
Internal Medicine - Cardiovascular Disease in Seattle, WA
About Isaac S. Dreyfus Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ISAAC S. DREYFUS MD (NPI 1104389923) is an individual cardiovascular disease provider in Seattle, Washington, licensed in Washington (MD61648231) and active in the NPI registry since April 2019. He is enrolled in Medicare PECOS, is affiliated with University Of Washington Medical Ctr, and is a graduate of Other (2019).
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
Isaac S. Dreyfus 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 Isaac Dreyfus 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
Lancaster, CA 93534
- Reassigned Medicare billing, California enrollment
- 13,921 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 2
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, WAHarborview Medical Center
Acute Care Hospitals · Seattle, WAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 98195 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 98195
SEATTLE, WA 98195
SEATTLE, WA 98195
SEATTLE, WA 98195
SEATTLE, WA 98195
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 Isaac Dreyfus's NPI number?
The NPI number for Isaac Dreyfus is 1104389923. It was assigned to this individual provider in the NPPES registry on April 9, 2019.
Where is Isaac Dreyfus located?
Isaac Dreyfus practices at 1959 NE Pacific St, Seattle, WA 98195. The listed phone number is (206) 520-5000.
What is Isaac Dreyfus's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.
Is Isaac Dreyfus enrolled in Medicare?
Yes. Isaac Dreyfus 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 Isaac Dreyfus's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Isaac Dreyfus reassigns Medicare benefits to 2 organizations: The Association Of University Physicians (Seattle, WA) and Southern California Permanente Medical Group (Lancaster, CA). 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 Isaac Dreyfus's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Isaac Dreyfus accept?
Health plans from Premera Blue Cross Blue Shield of Alaska and Providence Health Plan list Isaac Dreyfus 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 Isaac Dreyfus affiliated with any hospitals?
According to CMS data, Isaac Dreyfus is affiliated with University Of Washington Medical Ctr and Harborview Medical Center.
When was this NPI record last updated?
The NPPES record for Isaac Dreyfus was last updated on June 10, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Isaac S. Dreyfus, MD · NPI 1104389923
Cardiovascular Disease physician in Seattle, Washington. Individual provider, active in the CMS NPPES registry since April 9, 2019.
## Identity
- **NPI:** 1104389923 (Entity type: Individual)
- **Enumerated:** April 9, 2019
- **Primary specialty:** Internal Medicine - Cardiovascular Disease · taxonomy 207RC0000X
- **State license:** MD61648231 (Washington)
- **Sole proprietor:** No
## Practice location
- **Address:** 1959 NE PACIFIC ST, Seattle, WA 98195-0001
- **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); Southern California Permanente Medical Group (NPI 1982863783, Lancaster, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2019
## Record status
- **NPPES last updated:** June 10, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1104389923) · Data from the CMS NPPES public registry.