William O'Connor, M.D.
NPI 1639127632 · Family Medicine Physician · Vacaville, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William O'Connor, M.D. is a Family Medicine Physician provider in Vacaville, CA (NPI 1639127632).
Provider details
- NPI number
- 1639127632
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G048496 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
974 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 410 | $203 |
| 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 OrG2212 | 170 | $35 |
| Training for Self-Care Or Home Management, Each 15 Minutes97535 | 112 | $38 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 105 | $145 |
| Destruction of Skin Growth, 1-14 Growths17110 | 53 | $130 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 55 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 134 | 36 |
| Metoprolol Succinate | 117 | 32 |
| Metformin Hcl | 97 | 23 |
| Levothyroxine Sodium | 96 | 21 |
| Atorvastatin Calcium | 89 | 16 |
| Lisinopril | 65 | 17 |
| Ezetimibe | 57 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$629 across 14 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-04
- Last updated
- 2014-12-09
Frequently asked questions
- What is William O'Connor's NPI number?
- William O'Connor's National Provider Identifier (NPI) is 1639127632, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William O'Connor's specialty?
- William O'Connor is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William O'Connor located?
- William O'Connor's practice location on file with NPPES is 300 Mason St., Vacaville, CA 95688-4506.
- What is William O'Connor's phone number?
- The practice phone number listed in the NPPES registry for William O'Connor is (707) 446-0422.
- Does William O'Connor accept Medicare?
- William O'Connor is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William O'Connor's NPI active?
- Yes — William O'Connor's NPI (1639127632) is active in the NPPES registry as of the last update on 2014-12-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.