1. Home
  2. Directory
  3. California
  4. Greenbrae
  5. Internal Medicine
  6. NPI Profile

SUSAN SUN M.D.
NPI 1871685578
Internal Medicine in Greenbrae, CA

Active since September 29, 2006PECOS EnrolledAccepts Medicare Assignment
85.49/100
CMS Quality Rating
250 BON AIR ROAD, GREENBRAE, CA 94984(415) 925-7000 Get Directions Write a Review

NPPES record last updated: October 22, 2015. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Susan Sun M.d. NPPES

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

SUSAN SUN M.D. (NPI 1871685578) is an individual internal medicine provider in Greenbrae, California, licensed in California (G72947) and active in the NPI registry since September 2006. She is enrolled in Medicare PECOS and is a graduate of Harvard Medical School (1990).

NPPES Registry Identity

NPI1871685578
Entity TypeIndividualFemale
Primary Taxonomy207R00000X
Provider Legal NameSUSAN SUNCredential: M.D.
Location Address250 BON AIR ROADGreenbrae, CA 94984
Mailing Address250 Bon Air RoadGreenbrae, CA 94984 · (415) 925-7086 · Fax (415) 925-7008
Phone(415) 925-7000
Sole ProprietorNo
Medical School CMSHarvard Medical SchoolGraduated 1990
Enumeration DateSeptember 29, 2006
Last NPPES UpdateOctober 22, 2015
✔ NPI 1871685578 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Licenses✔ Licensed in CA · G72947✔ Licensed in NM · 98399
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.
Also ListedHospitalistTaxonomy 208M00000X · License 98399 (NM), G72947 (CA)
250 BON AIR ROAD, Greenbrae, CA 94984
Open in Google Maps ↗

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

Susan Sun 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 ID5395637904
PECOS Enrollment IDI20090825000767
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

2

Medicare enrollment records show Susan Sun reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Galen Inpatient Physicians PC
Same address
Hospitalist
250 BON AIR RD
Greenbrae, CA 94904
  • Reassigned Medicare billing, California enrollment
  • 962 clinicians in this Medicare group
NPI 1841037850 (415) 925-7000
Marin Hospitalist Medical Group, Inc.
Same address
Internal Medicine
250 BON AIR RD, 3RD FLOOR
Greenbrae, CA 94904
  • Reassigned Medicare billing, California enrollment
  • 82 clinicians in this Medicare group
NPI 1023041753 (415) 925-7545

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 7

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
403 services160 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.
238 services130 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
109 services107 patients
Hospital discharge day management, more than 30 minutes 99239
Hospital discharge day management over 30 minutes involves a detailed process to ensure a smooth transition from hospital to home. It includes final examinations, discussion of your hospital stay, post-discharge instructions, and coordinating follow-up care.
106 services104 patients
Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 99231
Follow-up hospital inpatient care is a daily service where a healthcare professional checks on your health progress during your hospital stay. Each session typically lasts 15 minutes, involving updates on your condition and adjustments to your treatment plan, if necessary.
81 services46 patients
Hospital discharge day management, 30 minutes or less 99238
Hospital discharge day management of 30 minutes or less includes finalizing your treatment, discussing your progress, and planning after-care at home. It ensures you're ready to leave the hospital and continue recovery safely.
41 services41 patients

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.

85.49/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Individually scored
Quality97.15
Improvement Activities0
Cost83.57

Referred Medical Equipment & Supplies CMS DME claims 2

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Portable gaseous oxygen system, rental; includes portable container, regulator, flowmeter, humidifier, cannula or mask, and tubing E0431
DME-Oxygen and Supplies · category DC000N
1 supplier32 claims32 services$14.96 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
1 supplier32 claims32 services$69.06 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

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 Susan Sun's NPI number?

The NPI number for Susan Sun is 1871685578. It was assigned to this individual provider in the NPPES registry on September 29, 2006.

Where is Susan Sun located?

Susan Sun practices at 250 Bon Air Road, Greenbrae, CA 94984. The listed phone number is (415) 925-7000.

What is Susan Sun's specialty?

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

Is Susan Sun enrolled in Medicare?

Yes. Susan Sun 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 Susan Sun's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Susan Sun reassigns Medicare benefits to 2 organizations: Galen Inpatient Physicians PC (Greenbrae, CA) and Marin Hospitalist Medical Group, Inc. (Greenbrae, CA). 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 Susan Sun's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Susan Sun was last updated on October 22, 2015. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.