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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

MARK J SEBASTIAN DMD
NPI 1477536027
Dentist in Federal Way, WA

Active since November 28, 2005PECOS Enrolled
33516 9TH AVE S, WESTHILL COURT BLDG 2, FEDERAL WAY, WA 98003(253) 941-6242(253) 952-2129 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

About Mark J Sebastian Dmd NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

MARK J SEBASTIAN DMD (NPI 1477536027) is an individual dentist in Federal Way, Washington, licensed in Washington (5374) and active in the NPI registry since November 2005. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1477536027
Entity TypeIndividualMale
Primary Taxonomy122300000X
Provider Legal NameMARK J SEBASTIANCredential: DMD
Location Address33516 9TH AVE S, WESTHILL COURT BLDG 2Federal Way, WA 98003-6322
Mailing Address33516 9th Ave S, Westhill Court Bldg 2Federal Way, WA 98003-6322 · (253) 941-6242 · Fax (253) 952-2129
Phone(253) 941-6242
Fax(253) 952-2129
Sole ProprietorNo
Enumeration DateNovember 28, 2005
Last NPPES UpdateJuly 13, 2026
✔ NPI 1477536027 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyDentistDental Providers
Taxonomy Code122300000X
License✔ Licensed in WA · 5374
Definition
A dentist is a person qualified by a doctorate in dental surgery (D.D.S.) or dental medicine (D.M.D.), licensed by the state to practice dentistry, and practicing within the scope of that license. There is no difference between the two degrees: dentists who have a DMD or DDS have the same education. Universities have the prerogative to determine what degree is awarded. Both degrees use the same curriculum requirements set by the American Dental Association's Commission on Dental Accreditation. Generally, three or more years of undergraduate education plus four years of dental school is required to graduate and become a general dentist. State licensing boards accept either degree as equivalent, and both degrees allow licensed individuals to practice the same scope of general dentistry. Additional post-graduate training is required to become a dental specialist.
33516 9TH AVE S, Federal Way, WA 98003
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Other Identifiers 1

Other0040673WA · Labor & Industries

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Mark J Sebastian Dmd is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency– Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 98003 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$97.43 typical visit price
range $63.67 – $189.37
Typical copayment $24.35 (range $15.91 – $47.34)
Most-billed visit code 99203
Established Patient
$78.74 typical visit price
range $21.12 – $155.00
Typical copayment $19.68 (range $5.28 – $38.75)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 4

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. ZAN XU DDS
Dentist
33516 9TH AVE S, SUITE 4
FEDERAL WAY, WA 98003
King County (253) 838-8830
THOMAS C PETEK PHD
Psychologist
33516 9TH AVE S, BLDG 1
FEDERAL WAY, WA 98003
King County (253) 838-2501
RICHARD WARREN BORTON PHD
Psychologist
33516 9TH AVE S, BLDG 1
FEDERAL WAY, WA 98003
King County (253) 838-2501
DR. TODD GARRET YOSHINO DDS
Dentist (General Practice)
33516 9TH AVE S, SUITE 3
FEDERAL WAY, WA 98003
King County (253) 815-0441

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 Mark Sebastian's NPI number?

The NPI number for Mark Sebastian is 1477536027. It was assigned to this individual provider in the NPPES registry on November 28, 2005.

Where is Mark Sebastian located?

Mark Sebastian practices at 33516 9th Ave S Westhill Court Bldg 2, Federal Way, WA 98003. The listed phone number is (253) 941-6242.

What is Mark Sebastian's specialty?

The primary specialty registered for this NPI is Dentist with taxonomy code 122300000X.

Is Mark Sebastian enrolled in Medicare?

Yes. Mark Sebastian is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Mark Sebastian was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 28 days 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.