Hyosun Ahn
Occupational Therapist · Sunnyvale, CA
Hyosun Ahn is an occupational therapist with a practice address in Sunnyvale, California, and NPI 1255820478, issued on May 3, 2018. Check the license (California 8597, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Hyosun Ahn
- Primary taxonomy
- Occupational Therapist 225X00000X
- License number
- 8597 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1039 E EL Camino Real, Sunnyvale, CA 94087
- Phone
- (408) 599-0088
- Enumerated
- May 3, 2018
- Record last updated
- May 3, 2018 (not updated in 8 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20240517002162); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest occupational therapist records → All 9,244 in California → Look up another NPI →
Also registered at 1039 E EL Camino Real
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Bernard Buemio, LPTAPhysical Therapy Assistant1053972364
- Chin Ah Maria KimPhysical Therapist1144701400
- Cindy LinSpeech-Language Pathologist1598424038
- Diep Nguyen, MSOTOccupational Therapist1528488780
- Shi Mian TeoSpeech-Language Pathologist1235673195
- Dipika VaidPhysical Therapist1063189777
Verify Hyosun Ahn in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 8597Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Bills Medicare through one group practice
- Orthopaedic And Neurological Rehab IncLaguna Woods, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Hyosun Ahn among 9,244 occupational therapist records in California
Hyosun Ahn is one of 9,244 occupational therapist records with a practice address in California. 9% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2018, is newer than 47% of them.
- NPI issued2018 · 47% of these records are older, 47% newer
- In a Medicare fileYes · 9% of these records are
- In the CMS Doctors and Clinicians fileYes · 10% of these records are
- Graduated2005 · median 2018 among the 910 with a school on file
- Record last updated2018 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 225X00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
40 occupational therapist records list a practice address in Sunnyvale
They are 40 of the 1,690 NPPES records with a practice address in Sunnyvale, and 9,244 occupational therapist records in California.
All 9,244 in California → Every provider in Sunnyvale → Occupational Therapist nationwide →
The 8 occupational therapist records with the nearest ZIP codes
- Heather Brockett, OTR/LSunnyvale, CA 940871033459979
- Rachel ClementeSunnyvale, CA 940871447421755
- Chantal Drovin, OTR/LSunnyvale, CA 940871538537642
- Daniel Hamilton, OTSunnyvale, CA 940871588176283
- Glenn HandokoSunnyvale, CA 940871831868645
- Amanda HuangSunnyvale, CA 940871427528157
- Maiko Ibay, OTR/LSunnyvale, CA 940871871267005
- Marlene Lamar, O.T.R.,C.H.T.Sunnyvale, CA 940871346341260
Common questions
What is Hyosun Ahn's NPI number?
Hyosun Ahn's National Provider Identifier (NPI) is 1255820478, issued on May 3, 2018. An NPI identifies a provider in billing; it is not a license.
Where is Hyosun Ahn located?
The NPPES record lists a practice address at 1039 E EL Camino Real, Sunnyvale, CA, 94087. Phone: (408) 599-0088. Providers update this record themselves, so call before visiting.
How can I verify Hyosun Ahn's license?
NPPES lists California license number 8597, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity 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.