Mark J. Sebastian, DMD
Dentist · Federal Way, WA
Mark J. Sebastian, DMD is a dentist with a practice address in Federal Way, Washington, and NPI 1477536027, issued on Nov 28, 2005. Check the license (Washington 5374, as entered in NPPES) with the Washington board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Mark J. Sebastian
- Credential
- DMD
- Primary taxonomy
- Dentist 122300000X
- License number
- 5374 WA
Self-reported in NPPES; status is on the state search - Practice location
- 33516 9TH Ave S, Federal Way, WA 98003
- Phone
- (253) 941-6242
- Enumerated
- Nov 28, 2005
- Record last updated
- Jul 13, 2026
- Fax
- (253) 952-2129
- Entity
- Type 1 · individual
8 nearest dentist records → All 2,767 in Washington → Look up another NPI →
Also registered at 33516 9TH Ave S
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Mark J. Sebastian in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Washington board licenses this profession
Search for license 5374Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Mark J. Sebastian among 2,767 dentist records in Washington
Mark J. Sebastian, DMD is one of 2,767 dentist records with a practice address in Washington. 60% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 98% newer
- In a Medicare fileNo · 60% of these records are
- In the CMS Doctors and Clinicians fileNo · under 1% of these records are
- Record last updated2026 · 64% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 122300000X and a Washington practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
53 dentist records list a practice address in Federal Way
They are 53 of the 2,770 NPPES records with a practice address in Federal Way, and 2,767 dentist records in Washington. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 2,767 in Washington → Every provider in Federal Way → Dentist nationwide →
The 8 dentist records with the nearest ZIP codes
- Margaret Chiu, DDSFederal Way, WA 980031972596682
- Daniel Chong, DDSFederal Way, WA 980031609854926
- Buu-Chau Do, DMDFederal Way, WA 980031730202680
- Simin Faghih-Nakhjiri, DDS, MSD, MSFederal Way, WA 980031043263585
- Briain Filbert, D.D.S.Federal Way, WA 980031447239900
- Jeong-Ku Hahn, DDSFederal Way, WA 980031275671646
- Steven Hopkins, DDSFederal Way, WA 980031003817503
- Richard Hwynn, DDSFederal Way, WA 980031043207715
Common questions
What is Mark J. Sebastian, DMD's NPI number?
Mark J. Sebastian, DMD's National Provider Identifier (NPI) is 1477536027, issued on Nov 28, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Mark J. Sebastian, DMD located?
The NPPES record lists a practice address at 33516 9TH Ave S, Federal Way, WA, 98003. Phone: (253) 941-6242. Providers update this record themselves, so call before visiting.
How can I verify Mark J. Sebastian, DMD's license?
NPPES lists Washington license number 5374, as entered by the provider. Search the Washington board that licenses this profession; the NPPES record confirms identity only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.