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MA SOMSOUK M.D.
NPI 1437296431
Internal Medicine - Gastroenterology in San Francisco, CA

Active since January 31, 2007PECOS EnrolledAccepts Medicare Assignment
91.85/100
CMS Quality Rating
1001 POTRERO AVE # 3D-2, BOX 0862, SAN FRANCISCO, CA 94110(415) 206-8823(415) 641-0745 Get Directions Write a Review

NPPES record last updated: November 6, 2014. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Ma Somsouk M.d. NPPES

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

MA SOMSOUK M.D. (NPI 1437296431) is an individual gastroenterology provider in San Francisco, California, licensed in California (A84310) and active in the NPI registry since January 2007. He is enrolled in Medicare PECOS and is a graduate of Harvard Medical School (2002).

NPPES Registry Identity

NPI1437296431
Entity TypeIndividualMale
Primary Taxonomy207RG0100X
Provider Legal NameMA SOMSOUKCredential: M.D.
Location Address1001 POTRERO AVE # 3D-2, BOX 0862San Francisco, CA 94110-3518
Mailing Address1001 Potrero Ave # 3d-2, Box 0862San Francisco, CA 94110-3518 · (415) 206-8823 · Fax (415) 641-0745
Phone(415) 206-8823
Fax(415) 641-0745
Sole ProprietorNo
Medical School CMSHarvard Medical SchoolGraduated 2002
Enumeration DateJanuary 31, 2007
Last NPPES UpdateNovember 6, 2014
✔ NPI 1437296431 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
License✔ Licensed in CA · A84310
Definition
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.
Also ListedInternal MedicineTaxonomy 207R00000X · License A84310 (CA)
1001 POTRERO AVE # 3D-2, San Francisco, CA 94110
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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

Ma Somsouk 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 ID3678667375
PECOS Enrollment IDI20070925000361
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

4

Medicare enrollment records show Ma Somsouk reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

City & County Of San Francisco
Same address
General Acute Care Hospital
1001 POTRERO AVE, BUILDING 5, WARD 1B
San Francisco, CA 94110
  • Reassigned Medicare billing, California enrollment
  • 1,573 clinicians in this Medicare group
NPI 1083648810 (415) 759-4067
University Of California Sfgh Medical Group
Same address
Gastroenterology
1001 POTRERO AVE, RM 305
San Francisco, CA 94110
  • Reassigned Medicare billing, California enrollment
  • 23 clinicians in this Medicare group
NPI 1578538609 (415) 206-3736
University Of California San Francisco
3.0 mi
Surgery
400 PARNASSUS AVE, MCB 300
San Francisco, CA 94143
  • Reassigned Medicare billing, California enrollment
  • 5,645 clinicians in this Medicare group
NPI 1346329380 (415) 353-2161
Ucsf Medical Group Business Services
3.0 mi
Internal Medicine
400 PARNASSUS AVE
San Francisco, CA 94122
  • Reassigned Medicare billing, California enrollment
  • 5,544 clinicians in this Medicare group
NPI 1477624104 (415) 353-2808

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 8

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.

Moderate sedation services provided by the same physician or other qualified health care professional performing a gastrointestinal endoscopic service that sedation supports, requiring the presence of an independent trained observer to assist in the monito G0500
Moderate sedation is a method where a physician uses medication to help you relax during a gastrointestinal endoscopy. An independent trained observer will be present to monitor your vital signs and ensure your safety throughout the procedure. It's a common and safe practice.
85 services83 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.
31 services21 patients
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239
This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.
30 services30 patients
Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385
This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.
26 services26 patients
Biopsy of large bowel using a flexible endoscope 45380
A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.
24 services24 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.
20 services18 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94110 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
$119.48 typical visit price
range $23.44 – $166.46
Typical copayment $29.87 (range $5.86 – $41.61)
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.

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.

91.85/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored as part of a group practice
Quality83.53
Promoting Interoperability100
Improvement Activities40
Cost68.01

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 Ma Somsouk's NPI number?

The NPI number for Ma Somsouk is 1437296431. It was assigned to this individual provider in the NPPES registry on January 31, 2007.

Where is Ma Somsouk located?

Ma Somsouk practices at 1001 Potrero Ave # 3d-2 Box 0862, San Francisco, CA 94110. The listed phone number is (415) 206-8823.

What is Ma Somsouk's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Ma Somsouk enrolled in Medicare?

Yes. Ma Somsouk 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 Ma Somsouk's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Ma Somsouk reassigns Medicare benefits to 4 organizations: City & County Of San Francisco (San Francisco, CA), University Of California Sfgh Medical Group (San Francisco, CA), University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, 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 Ma Somsouk'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 Ma Somsouk was last updated on November 6, 2014. 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.