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STEPHEN LOUIS WALSTON MD
NPI 1578887519
Internal Medicine in Mercer Island, WA

Active since March 19, 2010PECOS EnrolledAccepts Medicare Assignment
3236 78TH AVE SE STE 200, MERCER ISLAND, WA 98040(206) 386-9500(206) 386-9605 Get Directions Write a Review

NPPES record last updated: November 11, 2021. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Nov 11, 2021, Aug 10, 2021, Jun 17, 2021 and 1 more (4 updates tracked since 2021).

About Stephen Louis Walston Md NPPES

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

STEPHEN LOUIS WALSTON MD (NPI 1578887519) is an individual internal medicine provider in Mercer Island, Washington, licensed in Washington (MD60423761) and active in the NPI registry since March 2010. He is enrolled in Medicare PECOS, is affiliated with Swedish Medical Center / Cherry Hill, and is a graduate of University Of Texas Medical School At Houston (2010).

NPPES Registry Identity

NPI1578887519
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameSTEPHEN LOUIS WALSTONCredential: MD
Location Address3236 78TH AVE SE STE 200Mercer Island, WA 98040-3500
Mailing AddressPo Box 25608Salt Lake City, UT 84125-0608 · (206) 320-4476 · Fax (206) 568-7043
Phone(206) 386-9500
Fax(206) 386-9605
Sole ProprietorNo
Medical School CMSUniversity Of Texas Medical School At HoustonGraduated 2010
Enumeration DateMarch 19, 2010
Last NPPES UpdateNovember 11, 20214 updates tracked since enumeration
NPPES CertifiedNovember 11, 2021
✔ NPI 1578887519 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in WA · MD60423761
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
3236 78TH AVE SE STE 200, Mercer Island, WA 98040
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Other Identifiers 2

Medicaid2022131WA
Medicaid1578887519WA

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include PacificSource Health Plans, Premera Blue Cross Blue Shield of Alaska, Providence Health Plan.Insurance ›

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Stephen Louis Walston 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.

PECOS PAC ID9830335363
PECOS Enrollment IDI20140213000002
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.

Areas of Expertise CMS Part B claims 10

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
283 services143 patients
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439
An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.
79 services79 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
48 services44 patients
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204
This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.
19 services19 patients
Advance care planning, first 30 minutes 99497
Advance care planning is a process where you discuss your healthcare preferences with your doctor. This conversation, lasting up to 30 minutes, helps ensure your wishes are respected if you're unable to communicate them in the future. It's about your care, your way.
18 services18 patients
Administration of influenza virus vaccine G0008
The administration of the influenza virus vaccine, also known as the flu shot, is a simple procedure to protect against the flu. A healthcare provider injects a small dose of the vaccine into your arm. This stimulates your immune system to produce antibodies, which will help your body fight off the flu if exposed.
18 services17 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Swedish Medical Center / Cherry Hill

Acute Care Hospitals · Seattle, WA
3/5 CMS rating
OwnershipVoluntary non-profit - Church
CMS Certification Number500025
Location500 17th AvenueSeattle, WA 98122 · King County
Emergency services

Swedish Medical Center

Acute Care Hospitals · Seattle, WA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number500027
Location747 BroadwaySeattle, WA 98122 · King County
Emergency services Birthing friendly

Swedish Issaquah

Acute Care Hospitals · Issaquah, WA
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number500152
Location751 NE Blakely DrIssaquah, WA 98029 · King County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 98040 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
$143.76 typical visit price
range $63.67 – $189.37
Typical copayment $35.94 (range $15.91 – $47.34)
Most-billed visit code 99204
Established Patient
$111.00 typical visit price
range $21.12 – $155.00
Typical copayment $27.75 (range $5.28 – $38.75)
Most-billed visit code 99214
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 5

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

ANDREA H CHANG DO
Internal Medicine (Endocrinology, Diabetes & Metabolism)
3236 78TH AVE SE STE 200
MERCER ISLAND, WA 98040
King County (206) 386-9500
ALEXANDRA CECIL STYHL MD
Internal Medicine
3236 78TH AVE SE STE 200
MERCER ISLAND, WA 98040
King County (206) 275-5060
MS. BOYON YUN ARNP
Nurse Practitioner (Family)
3236 78TH AVE SE STE 200
MERCER ISLAND, WA 98040
King County (206) 275-5060
DR. KEITH ALEXANDER LUTHER MD
Internal Medicine
3236 78TH AVE SE STE 200
MERCER ISLAND, WA 98040
King County (206) 275-5060
REBECCA NEBEL ARNP
Nurse Practitioner (Family)
3236 78TH AVE SE STE 200
MERCER ISLAND, WA 98040
King County (206) 275-5060

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 Stephen Walston's NPI number?

The NPI number for Stephen Walston is 1578887519. It was assigned to this individual provider in the NPPES registry on March 19, 2010.

Where is Stephen Walston located?

Stephen Walston practices at 3236 78th Ave SE Ste 200, Mercer Island, WA 98040. The listed phone number is (206) 386-9500.

What is Stephen Walston's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Stephen Walston enrolled in Medicare?

Yes. Stephen Walston 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.

What insurance does Stephen Walston accept?

Health plans from PacificSource Health Plans, Premera Blue Cross Blue Shield of Alaska and Providence Health Plan list Stephen Walston 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 Stephen Walston affiliated with any hospitals?

According to CMS data, Stephen Walston is affiliated with Swedish Medical Center / Cherry Hill, Swedish Medical Center and Swedish Issaquah.

When was this NPI record last updated?

The NPPES record for Stephen Walston was last updated on November 11, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years 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.