Dr. William B. Ahnn, MD
- Medicare services, 2017
- 110
- Medicare patients, 2024
- 47
- Part D claims, 2022
- 14
- MIPS score, 2024
- 85
- Hospital affiliations
- 1
- Practice address
- 2101 N Waterman Ave, San Bernardino, CA 92404
- Practice phone
- Call (909) 883-8711
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
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Dr. William B. Ahnn is an anesthesiologist in San Bernardino, California
Dr. Ahnn practices at Dignity Health - St. Bernardine Medical Center in San Bernardino, California, part of CommonSpirit Health.
Dr. Ahnn's NPI, 1457338683, was assigned on December 29, 2005. Dr. Ahnn graduated from Seoul National University College of Medicine in 1969. Dr. Ahnn holds California license A31405.
- NPI
- 1457338683NPI Registry (opens in a new tab)
- Medicare PAC ID
- 0648239855
- NPI enumeration date
- December 29, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (909) 883-8711
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 83
- Medical school graduation
- 1969
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. William B. Ahnn practices at Dignity Health - St. Bernardine Medical Center in San Bernardino, California
Dr. Ahnn's primary practice is Dignity Health - St. Bernardine Medical Center, at 2101 N Waterman Ave, San Bernardino, CA 92404 in San Bernardino County. The practice phone is (909) 883-8711.
- Dignity Health - St. Bernardine Medical Center2101 N Waterman Ave, San Bernardino, CA 92404 · San Bernardino CountyPhone(909) 883-8711
Source: Dmand AI Affiliation Data
Dr. William B. Ahnn is affiliated with 1 site of care and 1 medical group
Dr. Ahnn's primary practice is Dignity Health - St. Bernardine Medical Center in San Bernardino, California, part of CommonSpirit Health. The medical group on file is Palm Spring Anesthesia.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. William B. Ahnn's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Ahnn practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Dignity Health - St. Bernardine Medical Center | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. William B. Ahnn is one of 6,593 anesthesiologists in California
Anesthesiology is Dr. Ahnn's primary specialty in the NPI Registry, under taxonomy code 207L00000X. Dr. Ahnn is board certified in anesthesiology by the American Board of Anesthesiology. Dmand AI has Dr. Ahnn's licenses on file in 4 states: California, Washington, Pennsylvania and Ohio.
Specialties and state licenses
- Anesthesiology, CaliforniaPrimary
- Washington license
- Pennsylvania license
- Ohio license
Anesthesiologists near Dr. Ahnn
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 B. Ahnn billed Medicare for 110 services in 2017
CMS data shows 110 Medicare services from Dr. Ahnn across 5 procedure codes in 2017, for 47 Medicare patients. Medicare paid $16,118 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Ahnn's Medicare services by type, 2016 to 2017
- 2016
- 2017
- Anesthesia
- 2016: 292017: 4659%
- Surgery
- 2016: 392017: 4310%
- Imaging
- 2016: 262017: 2119%
Dr. Ahnn compared with the California median for anesthesiologists, 2017
- Dr. Ahnn
- California median
- Medicare services
- 110vs 7253% above
- Medicare patients
- 47vs 14367% below
- Part D claims
- 14vs 2339% below
Medians across 5,562 anesthesiologists in California with Dmand AI profiles that report each measure.
Dr. Ahnn's most billed Medicare procedure codes, 2017
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. Ahnn?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Ahnn and other anesthesiologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. William B. Ahnn treated 47 Medicare patients in 2024, average age 72
CMS counts 47 Medicare patients who saw Dr. Ahnn in 2024. The largest group is 65 to 74, with 23 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 68% are also on Medicaid. Their average risk score is 3.16, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Ahnn's median patient age at 58, with 60% women.
Dr. Ahnn's Medicare patients by age, 2024
CMS leaves out age groups with fewer than 11 patients.
Dr. Ahnn's Medicare patients by sex, 2024
- Women2349%
- Men2451%
Chronic conditions among Dr. Ahnn's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis55%
- Diabetes49%
- Chronic kidney disease43%
- Atrial fibrillation40%
- Heart failure40%
- COPD32%
Share of Medicare patients with each condition. A patient can have several.
Dr. Ahnn's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 58
Patient panel by sex, all payers
- Women60%
- Men39%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. William B. Ahnn wrote 14 Medicare Part D claims in 2022
In 2022, Dr. Ahnn wrote 14 Medicare Part D claims. They cover 1 drug, with $133 in total drug cost.
Dr. Ahnn'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.
Source: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026
Dr. William B. Ahnn scored 85 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 85 out of 100 for Dr. Ahnn for performance year 2024, reported as part of a group. Dr. Ahnn accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Dr. Ahnn's MIPS scores, performance year 2024
- 85of 100Final score
- 70of 100Quality
- 40of 100Improvement Activities
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Sources: Doctors and Clinicians National Downloadable File (CMS); and Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Dr. William B. Ahnn received $6,023 in industry payments from 2016 to 2024
CMS Open Payments shows 68 general payments to Dr. Ahnn from 7 drug and device companies from 2016 to 2024. Food and beverage make up the largest share, 51% of the total. Mallinckrodt LLC paid the most, $4,769.
General payments to Dr. Ahnn by program year, 2016 to 2024
General payments to Dr. Ahnn by kind, 2016 to 2024
- Food and beverage$3,08051%
- Speaker and faculty fees$2,90048%
- Travel and lodging$431%
Companies that paid Dr. Ahnn the most, 2016 to 2024
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. William B. Ahnn graduated from Seoul National University College of Medicine
Dr. Ahnn graduated from Seoul National University College of Medicine in 1969.
- Medical school
- Board certified in anesthesiology
Source: Dmand AI Professional Profile Data
Dr. William B. Ahnn accepts plans from 1 insurance carrier
Dr. Ahnn is in network with 1 carrier, including CMS Medicare. Medicare plans come from the most carriers, 1. Check the plan with the practice before a visit.
- CMS Medicare
Source: Dmand AI Insurance Network Data
Sources for Dr. William B. Ahnn'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 | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy 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) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Clinician Public Reporting: Overall MIPS Performance (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 B. Ahnn
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 B. Ahnn's NPI number?
Dr. William B. Ahnn's NPI number is 1457338683. It was assigned on December 29, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. William B. Ahnn?
Dr. William B. Ahnn is an anesthesiologist in San Bernardino, California. The primary specialty in the NPI Registry is Anesthesiology Physician (taxonomy code 207L00000X).
Where does Dr. William B. Ahnn practice?
Dr. Ahnn practices at 2101 N Waterman Ave, San Bernardino, CA 92404. Dr. Ahnn's primary practice is Dignity Health - St. Bernardine Medical Center in San Bernardino, California, part of CommonSpirit Health.
What is Dr. William B. Ahnn's office phone number?
The practice phone on file for Dr. Ahnn is (909) 883-8711.
What is Dr. William B. Ahnn's medical license number?
Dr. Ahnn holds California license A31405, one of the licenses on file in 4 states.
Which states has Dr. William B. Ahnn been licensed in?
Dmand AI has state licenses on file for Dr. Ahnn in California (1977 to 2026), Washington (1977 to 1990), Pennsylvania (1974 to 1982) and Ohio (1975 to 1979).
Which hospitals is Dr. William B. Ahnn affiliated with?
Dr. Ahnn practices at Dignity Health - St. Bernardine Medical Center in San Bernardino, California.
What medical group is Dr. William B. Ahnn part of?
Dr. Ahnn is linked to Palm Spring Anesthesia.
Does Dr. William B. Ahnn accept Medicare?
Yes. CMS data shows Dr. Ahnn billed Medicare for 110 services in 2017, and Dr. Ahnn accepts Medicare assignment.
What is Dr. William B. Ahnn's MIPS score?
Dr. Ahnn's MIPS final score for performance year 2024 is 85 out of 100, reported as part of a group.
Show 8 more questionsShow fewer questions
How many Medicare patients does Dr. William B. Ahnn see?
CMS counts 47 Medicare patients who saw Dr. Ahnn in 2024, with an average age of 72.
Is Dr. William B. Ahnn board certified?
Yes. Dr. Ahnn is board certified in anesthesiology by the American Board of Anesthesiology.
What services does Dr. William B. Ahnn bill to Medicare?
In 2017, Dr. Ahnn's most billed Medicare services were anesthesia (01844), surgery: brain, spine and nerves (64447) and surgery: brain, spine and nerves (62322).
Where did Dr. William B. Ahnn go to medical school?
Dr. Ahnn graduated from Seoul National University College of Medicine in 1969.
What drugs does Dr. William B. Ahnn prescribe most?
In 2022 Medicare Part D data, Dr. Ahnn's most prescribed drugs by claims were Paxlovid (Eua).
Has Dr. William B. Ahnn received payments from drug or device companies?
CMS Open Payments shows $6,023 in general payments to Dr. Ahnn from 7 companies from 2016 to 2024. The largest total came from Mallinckrodt LLC.
How long has Dr. William B. Ahnn been practicing?
Dr. Ahnn graduated from medical school in 1969, 57 years ago.
What insurance does Dr. William B. Ahnn accept?
Dr. Ahnn is in network with 1 carrier, including CMS Medicare. Medicare plans come from the most carriers, 1. Check the plan with the practice before a visit.
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