Quick answers
- Which hospitals does Frank P. Castillo Jr. work at?
- Medicare's official clinician data lists Frank P. Castillo Jr. at 2 hospitals: John Muir Medical Center - Concord Campus and John Muir Medical Center - Walnut Creek Campus. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Frank P. Castillo Jr. see patients?
- Medicare's clinician data lists 1 practice location in Walnut Creek, CA. Call before your visit to confirm the address.
- What is Frank P. Castillo Jr.'s specialty?
- Medicare lists Nurse Practitioner as the primary specialty.
- Does Frank P. Castillo Jr. accept Medicare assignment?
- Yes. Medicare's clinician data says Frank P. Castillo Jr. accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- Does Frank P. Castillo Jr. offer telehealth?
- Medicare's clinician data says Frank P. Castillo Jr. offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Frank P. Castillo Jr.?
- (925) 937-7740, as listed in official Medicare / NPI Registry data.
- What is Frank P. Castillo Jr.'s NPI number?
- 1639623770. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Frank P. Castillo Jr. works
Medicare's Facility Affiliation Data lists Frank P. Castillo Jr. at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- John Muir Medical Center - Concord CampusConcord, CA · Acute Care Hospital · CCN 050496
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA · Acute Care Hospital · CCN 050180
Practice locations
Addresses where Frank P. Castillo Jr. is enrolled with Medicare (CMS data updated 2026-10-02).
- 100 N Wiget Ln, Suite 290Walnut Creek, CA 94598 (925) 937‑7740
Group practices
Medicare enrollment lists Frank P. Castillo Jr. as a member of this group (CMS data updated 2026-10-02).
- John Muir Physician Network494 clinicians in the group
Specialties
- Nurse Practitionerprimary
Other nurse practitioners in Walnut Creek
Clinicians with the same Medicare primary specialty in Walnut Creek, CA — not a recommendation.
Clinician information
| Credential | NP |
|---|---|
| Graduation year | 2016 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1639623770 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians