Jack Joon-Sung Choi, M.D.
Emergency Medicine Physician · Walnut Creek, CA
Jack Joon-Sung Choi, M.D. is an emergency medicine physician with a practice address in Walnut Creek, California, and NPI 1710186713, issued on Jul 11, 2007. Check the license (California A99061, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Jack Joon-Sung Choi
- Credential
- M.D.
- Primary taxonomy
- Emergency Medicine Physician 207P00000X
- License number
- A99061 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1425 S Main St, Walnut Creek, CA 94596
- Phone
- (510) 625-6262
- Enumerated
- Jul 11, 2007
- Record last updated
- Nov 18, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20071023000692); accepts Medicare assignment
- Medical or professional school
- Albert Einstein College Of Medicine Of Yeshiva University, 2002
- Entity
- Type 1 · individual
8 nearest emergency medicine physician records → All 7,751 in California → Look up another NPI →
Also registered at 1425 S Main St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Aaron Mark Acosta, DOEmergency Medicine Physician1538789987
- Basil Adad, MDOtolaryngology Physician1487732574
- Derek Ailes, M.D.Emergency Medical Services (Emergency Medicine) Physician1992001804
Verify Jack Joon-Sung Choi in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A99061Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% more Medicare Part D claims than the average emergency medicine physician in 2024
447 Medicare Part D claims for 364 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D.
Most prescribed
- Cefadroxil67 claims
- Amoxicillin-Clavulanate Potass45 claims
- Prednisone29 claims
- Doxycycline Monohydrate27 claims
- Albuterol Sulfate Hfa22 claims
- Nitrofurantoin Mono-Macro22 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Southern California Permanente Medical GroupSan Diego, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Jack Joon-Sung Choi among 7,751 emergency medicine physician records in California
Jack Joon-Sung Choi, M.D. is one of 7,751 emergency medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 40% of them.
- NPI issued2007 · 40% of these records are older, 50% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2002 · median 2011 among the 4,560 with a school on file
- Record last updated2021 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
95 emergency medicine physician records list a practice address in Walnut Creek
They are 95 of the 6,170 NPPES records with a practice address in Walnut Creek, and 7,751 emergency medicine physician records in California.
All 7,751 in California → Every provider in Walnut Creek → Emergency Medicine Physician nationwide →
The 8 emergency medicine physician records with the nearest ZIP codes
- Peter Barnett, M.D.Walnut Creek, CA 945961699882589
- Brian Baskin, MDWalnut Creek, CA 945961770554693
- Peter Benson, M.D.Walnut Creek, CA 945961487680393
- Scott Chamberlain, M.D.Walnut Creek, CA 945961356395453
- Charles Hansen, MDWalnut Creek, CA 945961891873956
- Christopher Jaksa, MDWalnut Creek, CA 945961619055779
- Conrad Lai, M.DWalnut Creek, CA 945961942248141
- Hannon Patel, MDWalnut Creek, CA 945961336227495
Common questions
What is Jack Joon-Sung Choi, M.D.'s NPI number?
Jack Joon-Sung Choi, M.D.'s National Provider Identifier (NPI) is 1710186713, issued on Jul 11, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Jack Joon-Sung Choi, M.D. located?
The NPPES record lists a practice address at 1425 S Main St, Walnut Creek, CA, 94596. Phone: (510) 625-6262. Providers update this record themselves, so call before visiting.
How can I verify Jack Joon-Sung Choi, M.D.'s license?
NPPES lists California license number A99061, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Jack Joon-Sung Choi, M.D. prescribe under Medicare Part D?
In 2024, Jack Joon-Sung Choi, M.D. had 447 Medicare Part D claims for 364 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.