Carl Jeffries Mason, M.D.
Internal Medicine Physician · Seattle, WA
Carl Jeffries Mason, M.D. is an internal medicine physician with a practice address in Seattle, Washington, and NPI 1184787525, issued on Dec 18, 2006. Check the license on the Washington Medical Commission; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Carl Jeffries Mason
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- MD038142E PA
Self-reported in NPPES; status is on the state search - Practice location
- 24 Roy St, Seattle, WA 98109
- Phone
- (805) 455-8593
- Enumerated
- Dec 18, 2006
- Record last updated
- Sep 25, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (805) 435-1509
- Entity
- Type 1 · individual
Also registered at 24 Roy St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Hibaq Ahmed Sudi Guled, M.EDBehavior Analyst1801294681
- Valori Berends, M.S., BCBABehavior Analyst1790089803
- Lacy CheersBehavior Analyst1952702441
- Iisha GwynnBehavior Analyst1932589280
- Kathleen Laino, M.S., BCBABehavior Analyst1366747933
Verify Carl Jeffries Mason in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWashington Medical CommissionCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
821 internal medicine physician records list a practice address in Seattle
They are 821 of the 41,956 NPPES records with a practice address in Seattle, and 3,079 internal medicine physician records in Washington. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 821 in Seattle → All 3,079 in Washington → Every provider in Seattle →
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- James Abbey, M.D.Anacortes, WA1447646039
- Joel Abbott, D.O.Tacoma, WA1477752723
- Paul Abdallah, MDSeattle, WA1639166119
- Abir Abdel-Kader, MDRichland, WA1649407081
- Hussein Abdille, MDSeattle, WA1588368831
Common questions
What is Carl Jeffries Mason, M.D.'s NPI number?
Carl Jeffries Mason, M.D.'s National Provider Identifier (NPI) is 1184787525, issued on Dec 18, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Carl Jeffries Mason, M.D. located?
The NPPES record lists a practice address at 24 Roy St, Seattle, WA, 98109. Phone: (805) 455-8593. Providers update this record themselves, so call before visiting.
How can I verify Carl Jeffries Mason, M.D.'s license?
Search the Washington Medical Commission at https://wahelms.my.site.com/s/license-search. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
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.