Doctor profile · Federal record

Dr. Diana Tsai, MD

Hospitalist Physician (CMS: Hospitalist) · Family Medicine Physician · Internal Medicine Physician · Mountain View, CA

  • NPI 1669534467
  • Accepts Medicare
  • 27 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
701 E El Camino Real
Mountain View, CA 940402833
(650) 934-7808
Mailing address
325 Distel Cir
Los Altos, CA 940221408

Credentials & registration

NPPES · NUCC
NPI registered
December 2006 — 20 yrs on file
Profile last updated
February 25, 2021
Year of graduation
1999 — 27 yrs since
Specialty taxonomy
208M00000X — NUCC code
State license (1)
California #A72927

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1669534467. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
463
Distinct HCPCS
5
Medicare allowed
$54,352
HCPCS Description Services Patients Avg allowed
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 273 117 $91
99239 Hospital discharge day management, more than 30 minutes 74 73 $134
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 52 51 $200
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 33 33 $149
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 31 23 $137

In context: peer comparison

Among 19 peers in this city , average services per provider: 136. This provider delivers 3.4× the peer median.

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Diana Tsai's medical specialty?
Dr. Diana Tsai practices Hospitalist Physician in Mountain View, CA.
Where does Dr. Diana Tsai practice?
Dr. Diana Tsai practices at 701 E El Camino Real, Mountain View, CA 940402833. Office phone: 6509347808.
What is Dr. Diana Tsai's NPI?
Dr. Diana Tsai's National Provider Identifier (NPI) is 1669534467, issued by NPPES.
Does Dr. Diana Tsai accept Medicare assignment?
Yes. Dr. Diana Tsai accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Diana Tsai commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Hospital discharge day management (HCPCS 99239); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.