Individual provider

Jason Harper, MD

Gastroenterology Physician Internal Medicine Physician Medicare enrolled

Jason Harper, MD is a Gastroenterology Physician in Seattle, WA, registered under NPI 1336305911. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.

Getting there

The practice address on file is 1221 MADISON ST STE 1220, Seattle, WA 98104. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.

1221 MADISON ST STE 1220, Seattle, WA 98104 Open in Google Maps →

Credentials and Medicare

State licence
LicenceStateSpecialty
MD60238161 WA Gastroenterology Physician primary
MD60238161 WA Internal Medicine Physician

This provider holds licence MD60238161 issued in WA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.

Medicare (PECOS)
Status
Approved
Provider type
Practitioner - Gastroenterology
PAC ID
8426273426
Enrollment ID
I20140708000812

Medicare enrolment is recorded as approved under the provider type Practitioner - Gastroenterology. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.

What Gastroenterology covers

An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs. NUCC Health Care Provider Taxonomy, code 207RG0100X
Allopathic & Osteopathic Physicians Internal Medicine Gastroenterology

All registered taxonomy codes

This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.

CodeSpecialtyLicenceState
207RG0100X Gastroenterology Physician Gastroenterology MD60238161 WA primary
207R00000X Internal Medicine Physician MD60238161 WA

The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.

Full NPPES record

An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.

NPI1336305911 valid check digit
Entity typeIndividual (NPI-1)
Enumeration dateAug 2, 2008
Last updatedJan 12, 2026
StatusActive
Sole proprietorNo
CredentialMD
Practice address 1221 MADISON ST STE 1220
Seattle, WA 98104
(206) 215-4250
Fax (206) 215-4252
Mailing address PO BOX 25608
Salt Lake City, UT 84125
Other identifiers 2018493 · Medicaid (WA)
This record was updated on Jan 12, 2026, which is recent enough that the contact details are likely still accurate.

Number check

1336305911 passes the NPI check digit test The final digit 1 matches the value computed from the first nine digits, so this is a well-formed NPI.
How the check works, step by step

Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.

Digit 8 0 8 4 0 1 3 3 6 3 0 5 9 1
Doubled? ×2 ×2 ×2 ×2 ×2 ×2 ×2
Value 8 0 8 8 0 2 3 6 6 6 0 1 9 2

Sum = 59 · next multiple of 10 = 60 · check digit = 1 · actual last digit = 1

A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.

Common questions

What is NPI number 1336305911?
NPI 1336305911 is the National Provider Identifier assigned to Jason Harper, MD in Seattle, WA. It is a 10-digit number issued by the Centers for Medicare & Medicaid Services and used on claims, referrals, and prescriptions to identify the provider.
What does Gastroenterology cover?
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes…
How do I contact Jason Harper, MD?
The phone number on file with NPPES is (206) 215-4250, last updated Jan 12, 2026. Because NPPES is only updated when a provider files a change, call ahead to confirm the number and the current practice address before visiting.
Does Jason Harper, MD accept Medicare?
This NPI has an approved Medicare enrolment in PECOS, which means the provider is enrolled to bill Medicare. Enrolment does not guarantee they are accepting new Medicare patients — verify directly with the office.
Is NPI 1336305911 a valid number?
Yes. 1336305911 passes the Luhn check digit validation that CMS uses for NPI numbers, and it resolves to an active record in the registry.
How to use this page. Everything here comes from public federal records. Tips Health does not verify quality of care, confirm that a licence is currently active, or check malpractice history, and accepts no fees for placement. A listing is not a recommendation. Verify independently before seeking care.