William To, PA
Physician Assistant · Garden Grove, CA
William To, PA is a physician assistant with a practice address in Garden Grove, California, and NPI 1336425644, issued on Nov 1, 2011. Check the license (California PA21861, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- William To
- Credential
- PA
- Primary taxonomy
- Physician Assistant 363A00000X
- License number
- PA21861 CA
Self-reported in NPPES; status is on the state search - Practice location
- 12555 Garden Grove Blvd Ste 504, Garden Grove, CA 92843
- Phone
- (714) 537-5609
- Enumerated
- Nov 1, 2011
- Record last updated
- Nov 1, 2011 (not updated in 15 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20140627002209); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 14,451 in California → Look up another NPI →
Verify William To in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license PA21861Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
56% fewer Medicare Part D claims than the average physician assistant in 2024
364 Medicare Part D claims for 110 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. 12 claims were for opioids.
Most prescribed
- Creon63 claims
- Ursodiol37 claims
- Metronidazole31 claims
- Neomycin Sulfate31 claims
- Pantoprazole Sodium21 claims
- Sulfamethoxazole-Trimethoprim19 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.
Industry payments in 2024: $125.00
1 payment: food and beverage; the largest payer was Abbvie Inc. The 64,719 providers of this specialty with any payment received $841.65 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- University Surgeons OF Orange A Medical GroupOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William To among 14,451 physician assistant records in California
William To, PA is one of 14,451 physician assistant records with a practice address in California. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2011, is newer than 30% of them.
- NPI issued2011 · 30% of these records are older, 67% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 50% of these records are
- Graduated2004 · median 2018 among the 7,214 with a school on file
- Record last updated2011 · 40% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
40 physician assistant records list a practice address in Garden Grove
They are 40 of the 4,572 NPPES records with a practice address in Garden Grove, and 14,451 physician assistant records in California.
All 14,451 in California → Every provider in Garden Grove → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Sandra Fineman, PAGarden Grove, CA 928431033425640
- Cortney Hayek, P.A.Garden Grove, CA 928431154334373
- Anna Heilig-Adams, PA-CGarden Grove, CA 928431669738423
- Rachel Kalter, PA-CGarden Grove, CA 928431285037358
- Wan Ling Low, PA-CGarden Grove, CA 928431770266231
- Mai Moiseshyn, PAGarden Grove, CA 928431437194693
- Lucy Paredes, PA-CGarden Grove, CA 928431881977965
- Saadia Parekh, PA-CGarden Grove, CA 928431174680821
Common questions
What is William To, PA's NPI number?
William To, PA's National Provider Identifier (NPI) is 1336425644, issued on Nov 1, 2011. An NPI identifies a provider in billing; it is not a license.
Where is William To, PA located?
The NPPES record lists a practice address at 12555 Garden Grove Blvd Ste 504, Garden Grove, CA, 92843. Phone: (714) 537-5609. Providers update this record themselves, so call before visiting.
How can I verify William To, PA's license?
NPPES lists California license number PA21861, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does William To, PA prescribe under Medicare Part D?
In 2024, William To, PA had 364 Medicare Part D claims for 110 beneficiaries; the average among physician assistant prescribers was 830. 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.