Doctor profile · Federal record

Dr. William O'Connor, M.D.

Family Medicine Physician (CMS: Family Practice) · Vacaville, CA

  • NPI 1639127632
  • Accepts Medicare
  • 45 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
300 Mason St.
Vacaville, CA 956884506
(707) 446-0422
fax (707) 446-1655

Credentials & registration

NPPES · NUCC
NPI registered
May 2006 — 20 yrs on file
Profile last updated
December 9, 2014
Year of graduation
1981 — 45 yrs since
Specialty taxonomy
207Q00000X — NUCC code
State license (1)
California #G048496
Medicaid
CA #00G484960

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1639127632. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
835
Distinct HCPCS
10
Medicare allowed
$120,618
HCPCS Description Services Patients Avg allowed
99215 Established patient office or other outpatient visit, 40-54 minutes 372 105 $197
G2212 Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or 144 65 $35
99214 Established patient office or other outpatient visit, 30-39 minutes 113 63 $133
97535 Training for self-care or home management, each 15 minutes 45 30 $38
11312 Shaving of skin growth of face, ears, eyelids, nose, lips, or mouth, 1.1-2.0 cm 38 18 $168
99213 Established patient office or other outpatient visit, 20-29 minutes 33 24 $90
17004 Destruction of precancer skin growth, 15 or more growths 30 14 $200
99205 New patient office or other outpatient visit, 60-74 minutes 27 27 $243
17000 Destruction of precancer skin growth, 1 growth 19 12 $60
11106 Incision biopsy, first skin growth 14 12 $187

In context: peer comparison

Among 14 peers in Vacaville Family Medicine Physician, average services per provider: 79. This provider delivers 11× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$629
Transactions
14
Manufacturers
6
Payer (manufacturer) Industry Txns Amount
Boehringer Ingelheim Pharmaceuticals, INC. 8 $271.42
Axsome Therapeutics, INC. 1 $121.83
Abbvie INC. 1 $102.96
AstraZeneca Pharmaceuticals Lp 2 $97.60
Pfizer INC. 1 $17.44
Takeda Pharmaceuticals U.S.A., INC. 1 $17.34

By nature of payment

Food and Beverage
$611
Education
$17

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
984
Patients
247
Total drug cost
$20,651
Drug Type Claims Patients Total cost
Metoprolol Succinate Generic 135 33 $3,060
Rosuvastatin Calcium Generic 132 36 $2,707
Levothyroxine Sodium Generic 100 22 $1,573
Metformin Hcl Generic 89 22 $781
Lisinopril Generic 85 18 $1,004
Amlodipine Besylate Generic 68 19 $593
Atorvastatin Calcium Generic 58 13 $713
Simvastatin Generic 50 15 $800
Hydrochlorothiazide Generic 45 12 $252
Ezetimibe Generic 42 0 $4,718

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. William O'Connor's medical specialty?
Dr. William O'Connor practices Family Medicine Physician in Vacaville, CA.
Where does Dr. William O'Connor practice?
Dr. William O'Connor practices at 300 Mason St., Vacaville, CA 956884506. Office phone: 7074460422.
What is Dr. William O'Connor's NPI?
Dr. William O'Connor's National Provider Identifier (NPI) is 1639127632, issued by NPPES.
Does Dr. William O'Connor accept Medicare assignment?
Yes. Dr. William O'Connor accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William O'Connor commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99215); Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or (HCPCS G2212); Established patient office or other outpatient visit (HCPCS 99214). Source: CMS Medicare Physician & Other Practitioners file.