DR. MARY STELLA LARSON M.D.
NPI 1982650040
Internal Medicine - Cardiovascular Disease in Redwood City, CA

Q: What is Mary Larson's NPI number?

The NPI number for Mary Larson is 1982650040. It was assigned to this individual provider in the NPPES registry on May 26, 2006.

Q: What is Mary Larson's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.

Q: When was this NPI record last updated?

The NPPES record for Mary Larson was last updated on July 23, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 months 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.

Active since May 26, 2006PECOS EnrolledAccepts Medicare Assignment

94.91/100

CMS Quality Rating

2900 WHIPPLE AVE, SUITE 230, REDWOOD CITY, CA 94062(650) 306-2300(650) 306-2336 Get Directions Write a Review

NPPES record last updated: July 23, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

On this page

About Dr. Mary Stella Larson M.d. NPPES

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

DR. MARY STELLA LARSON M.D. (NPI 1982650040) is an individual cardiovascular disease provider in Redwood City, California, licensed in California (G76435) and active in the NPI registry since May 2006. She is enrolled in Medicare PECOS, is affiliated with Kootenai Health, and maintains a secondary practice location in Coeur D Alene.

NPPES Registry Identity

NPI1982650040

Entity TypeIndividualFemale

Primary Taxonomy207RC0000X

Provider Legal NameDR. MARY STELLA LARSONCredential: M.D.

Location Address2900 WHIPPLE AVE, SUITE 230Redwood City, CA 94062-2843

Mailing Address3400 Data DriveRancho Cordova, CA 95670

Phone(650) 306-2300

Fax(650) 306-2336

Sole ProprietorNo

Medical School CMSOtherGraduated 1991

Enumeration DateMay 26, 2006

Last NPPES UpdateJuly 23, 2025

NPPES CertifiedJuly 23, 2025

✔ NPI 1982650040 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Cardiovascular DiseaseAllopathic & Osteopathic Physicians

Taxonomy Code207RC0000X

Licenses✔ Licensed in CA · G76435✔ Licensed in ID · M-15598

Definition

An internist who specializes in diseases of the heart and blood vessels and manages complex cardiac conditions such as heart attacks and life-threatening, abnormal heartbeat rhythms.

2900 WHIPPLE AVE, Redwood City, CA 94062

Open in Google Maps ↗

Secondary Practice Location 1

Location 1700 W Ironwood Dr Ste 350Coeur D Alene, ID 83814-4487 · Phone (208) 625-5250 · Fax (208) 625-5251

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter Health, Moda Health Plan, Inc., Molina Healthcare and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Mary Stella Larson M.d. 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 ID7214020544

PECOS Enrollment IDI20230217001262

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.

Medicare Billing Reassignments

Medicare enrollment records show Mary Larson reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Kootenai Health, Inc.

758 mi

Psychiatry

2003 KOOTENAI HEALTH WAY
Coeur D Alene, ID 83814

Reassigned Medicare billing, Idaho enrollment
472 clinicians in this Medicare group

NPI 1174661151 (208) 625-4000

Kootenai Health, Inc.

758 mi

Psychiatry

2003 KOOTENAI HEALTH WAY
Coeur D Alene, ID 83814

Reassigned Medicare billing, Idaho enrollment
301 clinicians in this Medicare group

NPI 1174661151 (208) 625-4000

Boundary Community Hospital

830 mi

Emergency Medical Services

6640 KANIKSU ST
Bonners Ferry, ID 83805

Reassigned Medicare billing, Idaho enrollment
83 clinicians in this Medicare group

NPI 1679621098 (208) 267-4850

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 24

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.

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 93010

A routine electrocardiogram (ECG) with 12 leads is a simple, non-invasive test that records the electrical activity of your heart. It helps in identifying heart conditions by detecting irregularities in your heart rhythms. The results are interpreted and a report is provided.

883 services741 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 93306

This is a heart ultrasound, also known as an echocardiogram. It uses sound waves to create pictures of your heart, showing how blood flows through it. The color depicts the blood flow's speed and direction. It also checks the heart's valves to ensure they're working properly.

412 services410 patients

Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 93306

162 services161 patients

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.

154 services136 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 93010

122 services119 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

111 services61 patients

Exercise or drug-induced heart stress test with electrocardiogram (ecg) with supervision by physician 93016

An exercise or drug-induced heart stress test with ECG involves monitoring your heart's activity while it's under stress, either from exercise or medication. A doctor supervises the entire procedure to ensure safety and accuracy in results. This test helps detect heart problems.

109 services109 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.

94 services94 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

90 services90 patients

Ultrasound of heart with color-depicted blood flow, rate and valve function 93325

An ultrasound of the heart, also known as an echocardiogram, uses sound waves to create pictures of your heart. It shows the structure, movement, and blood flow within your heart. This helps assess the heart's health and function, including the valves and rate.

57 services53 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

57 services49 patients

Exercise or drug-induced heart stress test with electrocardiogram (ecg) with review by physician 93018

An exercise or drug-induced heart stress test with ECG is a procedure to assess how your heart functions under stress. It can involve exercising or medication to make your heart work harder while an ECG records its activity. A physician reviews the results.

45 services44 patients

Ultrasound of heart, follow-up 93308

A follow-up ultrasound of the heart, also known as an echocardiogram, is a non-invasive test that uses sound waves to create images of your heart. It helps doctors monitor your heart's function and structures after initial assessment or treatment.

42 services40 patients

Ultrasound of heart blood flow, valves and chambers, follow-up 93321

This procedure, an echocardiogram, uses sound waves to create images of your heart. It aids in assessing your heart's blood flow, chambers, and valves. It's a follow-up procedure, ensuring that your heart is functioning properly post-treatment.

41 services40 patients

Heart rhythm review and interpretation of continous external ekg over 8-15 days 93248

This service involves wearing a device for 8-15 days that continuously records your heart's electrical activity. It helps in identifying irregular heart rhythms. The recorded data is then reviewed and interpreted by a healthcare professional for any abnormalities.

35 services35 patients

Heart rhythm review and interpretation of continous external ekg over 8-15 days 93248

34 services34 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

32 services30 patients

Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222

Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.

32 services32 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 93000

An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.

25 services23 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

24 services23 patients

Heart rhythm review, and interpretation of continous external ekg over more than 48 hours up to 7 days 93244

A heart rhythm review involves monitoring your heart's electrical activity for more than 48 hours up to 7 days. Using a device called an external EKG, doctors can track your heartbeats to detect irregularities and help diagnose heart conditions.

20 services20 patients

Ultrasound of heart with probe in esophagus, with report 93312

This procedure, called a transesophageal echocardiogram, uses a small probe passed into your esophagus to capture detailed images of your heart. The report provides information about your heart's structure and function.

18 services18 patients

Heart rhythm review, and interpretation of continous external ekg over more than 48 hours up to 7 days 93244

13 services13 patients

New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205

This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.

11 services11 patients

Hospital Affiliations CMS Care Compare 5

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

Kootenai Health

Acute Care Hospitals · Coeur D'alene, ID

4/5 CMS rating

OwnershipGovernment - Hospital District or Authority

CMS Certification Number130049

Location2003 Kootenai Health WayCoeur D'alene, ID 83814 · Kootenai County

Emergency services Birthing friendly

Boundary Community Hospital

Critical Access Hospitals · Bonners Ferry, ID

OwnershipVoluntary non-profit - Other

CMS Certification Number131301

Location6640 Kaniksu StreetBonners Ferry, ID 83805 · Boundary County

Emergency services

Clearwater Valley Hospital & Clinics

Critical Access Hospitals · Orofino, ID

OwnershipVoluntary non-profit - Private

CMS Certification Number131320

Location301 Cedar StreetOrofino, ID 83544 · Clearwater County

Emergency services

St Marys Hospital And Clinics

Critical Access Hospitals · Cottonwood, ID

OwnershipVoluntary non-profit - Private

CMS Certification Number131321

Location701 Lewiston StCottonwood, ID 83522 · Idaho County

Emergency services

Gritman Medical Center

Critical Access Hospitals · Moscow, ID

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number131327

Location700 South Main StreetMoscow, ID 83843 · Latah County

Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94062 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

$153.83 typical visit price

range $69.00 – $202.35

Typical copayment $38.45 (range $17.25 – $50.58)

Most-billed visit code 99204

Established Patient

$84.91 typical visit price

range $23.44 – $166.46

Typical copayment $21.22 (range $5.86 – $41.61)

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.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

94.91/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored through an Alternative Payment Model

Quality

87.83

Promoting Interoperability

100

Improvement Activities

Other Providers at the Same Location NPPES 20

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

DUC MARCEL NGUYEN MD

Specialist

2900 WHIPPLE AVE, STE 115
REDWOOD CITY, CA 94062

San Mateo County (650) 365-5996

DR. BARRETT BRYAN MD

Internal Medicine

2900 WHIPPLE AVE, SUITE 130
REDWOOD CITY, CA 94062

San Mateo County (650) 298-8774

DR. JAMES JEROME ZIMMERMAN M.D.

Surgery (Vascular Surgery)

2900 WHIPPLE AVE, SUITE 225
REDWOOD CITY, CA 94062

San Mateo County (650) 366-0225

MS. VIRGINIA MORROW MSN, ANP

Nurse Practitioner

2900 WHIPPLE AVE, SUITE 245
REDWOOD CITY, CA 94062

San Mateo County (650) 365-3700

DR. BETTY HO M.D.

Internal Medicine (Gastroenterology)

2900 WHIPPLE AVE, STE 245
REDWOOD CITY, CA 94062

San Mateo County (650) 365-2911

MS. JENNIFER ROSE SUTTON PA-C

Physician Assistant (Medical)

2900 WHIPPLE AVE, SUITE 210
REDWOOD CITY, CA 94062

San Mateo County (650) 366-4542

SEQUOIA MEDICAL ASSOCIATES

Internal Medicine

2900 WHIPPLE AVE, SUITE 130
REDWOOD CITY, CA 94062

San Mateo County (650) 298-8774

MRS. SIGAL ALONA TENE MD

Internal Medicine (Critical Care Medicine)

2900 WHIPPLE AVE, STE 115
REDWOOD CITY, CA 94062

San Mateo County (650) 368-8981

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 Mary Larson's NPI number?

The NPI number for Mary Larson is 1982650040. It was assigned to this individual provider in the NPPES registry on May 26, 2006.

Where is Mary Larson located?

Mary Larson practices at 2900 Whipple Ave Suite 230, Redwood City, CA 94062. The listed phone number is (650) 306-2300.

What is Mary Larson's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.

Is Mary Larson enrolled in Medicare?

Yes. Mary Larson 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.

Which organizations bill Medicare for Mary Larson's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mary Larson reassigns Medicare benefits to 3 organizations: Kootenai Health, Inc. (Coeur D Alene, ID), Kootenai Health, Inc. (Coeur D Alene, ID) and Boundary Community Hospital (Bonners Ferry, ID). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Mary Larson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Mary Larson accept?

Health plans from Ambetter Health, Moda Health Plan, Inc., Molina Healthcare, PacificSource Health Plans and Premera Blue Cross Blue Shield of Alaska and 1 other insurer list Mary Larson 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 Mary Larson affiliated with any hospitals?

According to CMS data, Mary Larson is affiliated with Kootenai Health, Boundary Community Hospital, Clearwater Valley Hospital & Clinics, St Marys Hospital And Clinics and Gritman Medical Center.

When was this NPI record last updated?

The NPPES record for Mary Larson was last updated on July 23, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 months 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.