Doctor profile · Federal record

Dr. William Tatomer, MD

Psychiatry Physician (CMS: Psychiatry) · San Mateo, CA

  • NPI 1104862689
  • 55 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
101 S San Mateo Dr, Suite 300
San Mateo, CA 944013819
(650) 342-4442
fax (650) 342-8816

Credentials & registration

NPPES · NUCC
NPI registered
June 2006 — 20 yrs on file
Profile last updated
April 16, 2010
Year of graduation
1971 — 55 yrs since
Specialty taxonomy
2084P0800X — NUCC code
State license (1)
California #C35537

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1104862689. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
547
Distinct HCPCS
2
Medicare allowed
$43,217
HCPCS Description Services Patients Avg allowed
90836 Psychotherapy with evaluation and management visit, 45 minutes 274 41 $93
99212 Established patient office or other outpatient visit, 10-19 minutes 273 41 $65

In context: peer comparison

Among 8 peers in this city , average services per provider: 82. This provider delivers 6.7× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
267
Patients
0
Total drug cost
$52,706
Drug Type Claims Patients Total cost
Clonazepam Generic 35 0 $302
Sertraline Hcl Generic 35 0 $288
Escitalopram Oxalate Generic 33 0 $745
Trazodone Hcl Generic 32 0 $377
Fluoxetine Hcl Generic 21 0 $213
Vraylar (Cariprazine Hcl) Brand 20 0 $44,499
Lamotrigine Generic 19 0 $101
Venlafaxine Hcl Er (Venlafaxine Hcl) Brand 15 0 $916
Alprazolam Er (Alprazolam) Brand 12 0 $281
Gabapentin Generic 12 0 $554

Frequently asked questions

Auto-generated from federal data
What is Dr. William Tatomer's medical specialty?
Dr. William Tatomer practices Psychiatry Physician in San Mateo, CA.
Where does Dr. William Tatomer practice?
Dr. William Tatomer practices at 101 S San Mateo Dr, San Mateo, CA 944013819. Office phone: 6503424442.
What is Dr. William Tatomer's NPI?
Dr. William Tatomer's National Provider Identifier (NPI) is 1104862689, issued by NPPES.
Does Dr. William Tatomer accept Medicare assignment?
Dr. William Tatomer does not accept Medicare assignment for all services. Patients may be billed amounts beyond Medicare-allowed charges.
What procedures does Dr. William Tatomer commonly perform?
Top Medicare-reported procedures in 2023: Psychotherapy with evaluation and management visit (HCPCS 90836); Established patient office or other outpatient visit (HCPCS 99212). Source: CMS Medicare Physician & Other Practitioners file.