Dr. William Thomas Halsey, MD
- Medicare services, 2024
- 105
- Medicare patients, 2024
- 76
- Part D claims, 2024
- 38
- Industry payments
- $35
- Affiliated sites
- 3
- Practice address
- 111 Sonoma Ridge Rd, Santa Rosa, CA 95404
- Practice phone
- Call (707) 523-4907
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Santa Rosa Ambulatory Surgical Center Medical Group Inc
Santa Rosa, California
Find Dr. Halsey's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. William Thomas Halsey is an anesthesiologist in Santa Rosa, California
Dr. Halsey practices at Santa Rosa Ambulatory Surgical Center Medical Group Inc in Santa Rosa, California.
Dr. Halsey's NPI, 1295775237, was assigned on June 7, 2006. Dr. Halsey graduated from UTMB Health in 1974. Dr. Halsey holds California license C37471.
- NPI
- 1295775237NPI Registry (opens in a new tab)
- NPI enumeration date
- June 7, 2006
- NPI status
- Active
- Practice phone
- (707) 523-4907
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 78
- Medical school graduation
- 1974
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Practice Data
Dr. William Thomas Halsey practices at Santa Rosa Ambulatory Surgical Center Medical Group Inc in Santa Rosa, California
Dr. Halsey's primary practice is Santa Rosa Ambulatory Surgical Center Medical Group Inc, at 111 Sonoma Ridge Rd, Santa Rosa, CA 95404 in Sonoma County. The practice phone is (707) 523-4907.
- Santa Rosa Ambulatory Surgical Center Medical Group Inc111 Sonoma Ridge Rd, Santa Rosa, CA 95404 · Sonoma CountyPhone(707) 523-4907
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. William Thomas Halsey is affiliated with 4 sites of care and 2 medical groups
Dr. Halsey's primary practice is Santa Rosa Ambulatory Surgical Center Medical Group Inc in Santa Rosa, California. The medical group on file is Anesthesia Care Associates Medical Group. Dmand AI also links Dr. Halsey to 2 more group practices and clinics, 1 physician office and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. William Thomas Halsey's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Halsey practices, 3 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Santa Rosa Ambulatory Surgical Center Medical Group Inc | Available with a free account |
| +3 more sites and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. William Thomas Halsey is one of 6,593 anesthesiologists in California
Anesthesiology is Dr. Halsey's primary specialty in the NPI Registry, under taxonomy code 207L00000X. Dr. Halsey is board certified in anesthesiology by the American Board of Anesthesiology. Dmand AI has Dr. Halsey's licenses on file in 2 states: California and Texas.
Specialties and state licenses
- Anesthesiology, CaliforniaPrimary
- Texas license
Anesthesiologists near Dr. Halsey
Counts of anesthesiologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. William Thomas Halsey billed Medicare for 105 services in 2024
CMS data shows 105 Medicare services from Dr. Halsey across 3 procedure codes in 2024, for 76 Medicare patients. Medicare paid $16,927 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Halsey's Medicare services by type, 2020 to 2024
- 2020
- 2024
- Anesthesia
- 2020: 182024: 105483%
Dr. Halsey compared with the California median for anesthesiologists, 2024
- Dr. Halsey
- California median
- Medicare services
- 105vs 7246% above
- Medicare patients
- 76vs 14347% below
- Part D claims
- 12vs 2348% below
Medians across 5,562 anesthesiologists in California with Dmand AI profiles that report each measure.
Dr. Halsey's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
Need commercial claims for Dr. Halsey?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Halsey and other anesthesiologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. William Thomas Halsey treated 76 Medicare patients in 2024, average age 70
CMS counts 76 Medicare patients who saw Dr. Halsey in 2024. The largest group is 65 to 74, with 41 patients. 75% of them have high blood pressure, and 74% have high cholesterol. 41% are also on Medicaid. Their average risk score is 1.18, where 1.00 is the Medicare average.
Across all payers, Dmand AI patient panel data puts Dr. Halsey's median patient age at 72, with 51% women.
Dr. Halsey's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Halsey's Medicare patients by sex, 2024
- Women4661%
- Men3039%
Chronic conditions among Dr. Halsey's Medicare patients, 2024
- High blood pressure75%
- High cholesterol74%
- Arthritis72%
- Mood disorders37%
- Depression36%
- Diabetes33%
- Anxiety29%
- COPD21%
Share of Medicare patients with each condition. A patient can have several.
Dr. Halsey's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 72
Patient panel by sex, all payers
- Women51%
- Men49%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. William Thomas Halsey wrote 38 Medicare Part D claims in 2024
In 2024, Dr. Halsey wrote 38 Medicare Part D claims. 95% of them were for generic drugs. CMS names the drug for 12 of them, across 1 drug with 11 or more claims each, at $110 in total drug cost. In 2021, CMS named 47 claims across 4 drugs.
Dr. Halsey's Part D claims by kind of drug, 2024
- Generic36 claims95%
- Brand-name and other2 claims5%
Dr. Halsey's most prescribed drugs by claims, 2022
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Part D claims for drugs CMS names, 2021 to 2022
- 2021
- 2022
- Claims for drugs CMS names
- 2021: 472022: 1274%
Drugs named by CMS: 1 in 2022, 4 in 2021.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
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Dr. William Thomas Halsey received $35 in industry payments in 2020
CMS Open Payments shows 2 general payments to Dr. Halsey from 1 drug or device company in 2020. Food and beverage make up the largest share, 100% of the total. Halyard Health, Inc. paid the most, $35.
Companies that paid Dr. Halsey the most, 2020 to 2020
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. William Thomas Halsey graduated from UTMB Health
Dr. Halsey graduated from UTMB Health in 1974.
- Medical school
- Board certified in anesthesiology
Source: Dmand AI Professional Profile Data
Dr. William Thomas Halsey accepts plans from 6 insurance carriers
Dr. Halsey is in network with 6 carriers, including United Healthcare, Aspirus Health Plan and Blue Cross and Blue Shield of Kansas City. PPO plans come from the most carriers, 3. Check the plan with the practice before a visit.
- United Healthcare
- Aspirus Health Plan
- Blue Cross and Blue Shield of Kansas City
- Elevance
- HCSC
- NV State Medicaid
Plan types Dr. Halsey accepts, by number of carriers
- PPO3
- POS2
- EPO1
- HMO1
- Medicaid1
- Medicare1
Source: Dmand AI Insurance Network Data
Sources for Dr. William Thomas Halsey's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| Insurance carriers and plan types | Dmand AI Insurance Network Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. William Thomas Halsey
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. William Thomas Halsey's NPI number?
Dr. William Thomas Halsey's NPI number is 1295775237. It was assigned on June 7, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. William Thomas Halsey?
Dr. William Thomas Halsey is an anesthesiologist in Santa Rosa, California. The primary specialty in the NPI Registry is Anesthesiology Physician (taxonomy code 207L00000X).
Where does Dr. William Thomas Halsey practice?
Dr. Halsey practices at 111 Sonoma Ridge Rd, Santa Rosa, CA 95404. Dr. Halsey's primary practice is Santa Rosa Ambulatory Surgical Center Medical Group Inc in Santa Rosa, California. Dmand AI also links Dr. Halsey to 2 group practices and clinics, 1 physician office and 1 medical group.
What is Dr. William Thomas Halsey's office phone number?
The practice phone on file for Dr. Halsey is (707) 523-4907.
What is Dr. William Thomas Halsey's medical license number?
Dr. Halsey holds California license C37471, one of the licenses on file in 2 states.
Which states has Dr. William Thomas Halsey been licensed in?
Dmand AI has state licenses on file for Dr. Halsey in California (1977 to 2026) and Texas (1974 to 1992).
What medical group is Dr. William Thomas Halsey part of?
Dr. Halsey is linked to Anesthesia Care Associates Medical Group. Dmand AI links Dr. Halsey to 1 more medical group.
Does Dr. William Thomas Halsey accept Medicare?
Yes. CMS data shows Dr. Halsey billed Medicare for 105 services in 2024.
How many Medicare patients does Dr. William Thomas Halsey see?
CMS counts 76 Medicare patients who saw Dr. Halsey in 2024, with an average age of 70.
Is Dr. William Thomas Halsey board certified?
Yes. Dr. Halsey is board certified in anesthesiology by the American Board of Anesthesiology.
Show 6 more questionsShow fewer questions
What services does Dr. William Thomas Halsey bill to Medicare?
In 2024, Dr. Halsey's most billed Medicare services were anesthesia (00630), anesthesia (00600) and anesthesia (01160).
Where did Dr. William Thomas Halsey go to medical school?
Dr. Halsey graduated from UTMB Health in 1974.
What drugs does Dr. William Thomas Halsey prescribe most?
In 2022 Medicare Part D data, Dr. Halsey's most prescribed drugs by claims were Losartan Potassium.
Has Dr. William Thomas Halsey received payments from drug or device companies?
CMS Open Payments shows $35 in general payments to Dr. Halsey from 1 company from 2020 to 2020. The largest total came from Halyard Health, Inc.
How long has Dr. William Thomas Halsey been practicing?
Dr. Halsey graduated from medical school in 1974, 52 years ago.
What insurance does Dr. William Thomas Halsey accept?
Dr. Halsey is in network with 6 carriers, including United Healthcare, Aspirus Health Plan and Blue Cross and Blue Shield of Kansas City. PPO plans come from the most carriers, 3. Check the plan with the practice before a visit.
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