Doctor profile · Federal record

Dr. Mai-Sie Chan, MD

Internal Medicine Physician (CMS: Internal Medicine) · San Francisco, CA

  • NPI 1326136557
  • Accepts Medicare
  • 25 yrs in practice
  • Female
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
929 Clay St, Suite 303
San Francisco, CA 941081556
(415) 956-6633
fax (415) 956-6638

Credentials & registration

NPPES · NUCC
NPI registered
October 2006 — 20 yrs on file
Profile last updated
February 14, 2023
Year of graduation
2001 — 25 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A83362
Medicaid
CA #00A833620

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1326136557. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
771
Distinct HCPCS
9
Medicare allowed
$89,437
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 390 138 $145
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 101 101 $157
99213 Established patient office or other outpatient visit, 20-29 minutes 87 57 $89
G0008 Administration of influenza virus vaccine 68 68 $37
90662 Influenza vaccine split virus, preservative free 58 58 $72
93000 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 22 20 $18
99442 Telephone medical discussion with physician, 11-20 minutes 19 15 $75
99441 Telephone medical discussion with physician, 5-10 minutes 15 11 $40
90686 Influenza vaccine, quadrivalent, preservative free, 0.5 ml dosage 11 11 $22

In context: peer comparison

Among 236 peers in this city , average services per provider: 93. This provider delivers 8.3× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
2,829
Patients
811
Total drug cost
$205,400
Drug Type Claims Patients Total cost
Losartan Potassium Generic 511 138 $10,493
Amlodipine Besylate Generic 472 130 $7,915
Atorvastatin Calcium Generic 454 130 $8,699
Metformin Hcl Generic 188 51 $3,036
Metoprolol Succinate Generic 168 46 $3,615
Omeprazole Generic 136 48 $2,045
Simvastatin Generic 134 36 $2,773
Hydrochlorothiazide Generic 121 31 $1,440
Lisinopril Generic 96 27 $1,511
Diclofenac Sodium Generic 94 46 $3,570

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Mai-Sie Chan's medical specialty?
Dr. Mai-Sie Chan practices Internal Medicine Physician in San Francisco, CA.
Where does Dr. Mai-Sie Chan practice?
Dr. Mai-Sie Chan practices at 929 Clay St, San Francisco, CA 941081556. Office phone: 4159566633.
What is Dr. Mai-Sie Chan's NPI?
Dr. Mai-Sie Chan's National Provider Identifier (NPI) is 1326136557, issued by NPPES.
Does Dr. Mai-Sie Chan accept Medicare assignment?
Yes. Dr. Mai-Sie Chan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mai-Sie Chan commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (HCPCS G0439); Established patient office or other outpatient visit (HCPCS 99213). Source: CMS Medicare Physician & Other Practitioners file.