Quick answers
- Which hospitals does Corey M. Warner work at?
- Medicare's official clinician data lists Corey M. Warner at 4 hospitals: Adventist Health Clearlake, Adventist Health St Helena, Adventist Health Ukiah Valley and Sutter Lakeside Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Corey M. Warner see patients?
- Medicare's clinician data lists 1 practice location in Clearlake, CA. Call before your visit to confirm the address.
- What is Corey M. Warner's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Corey M. Warner accept Medicare assignment?
- Yes. Medicare's clinician data says Corey M. Warner 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.
- What is the phone number for Corey M. Warner?
- (707) 994-6486, as listed in official Medicare / NPI Registry data.
- What is Corey M. Warner's NPI number?
- 1801998968. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Corey M. Warner works
Medicare's Facility Affiliation Data lists Corey M. Warner at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Adventist Health ClearlakeClearlake, CA · Critical Access Hospital · CCN 051317
- Adventist Health St HelenaSaint Helena, CA · Acute Care Hospital · CCN 050013
- Adventist Health Ukiah ValleyUkiah, CA · Acute Care Hospital · CCN 050301
- Sutter Lakeside HospitalLakeport, CA · Critical Access Hospital · CCN 051329
Practice locations
Addresses where Corey M. Warner is enrolled with Medicare (CMS data updated 2026-10-02).
- 15630 18th AveClearlake, CA 95422 (707) 994‑6486
Group practices
Medicare enrollment lists Corey M. Warner as a member of this group (CMS data updated 2026-10-02).
- Adventist Health Clearlake Hospital Inc.87 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Clearlake
Clinicians with the same Medicare primary specialty in Clearlake, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Oregon Health Sciences University School Of Medicine |
| Graduation year | 1997 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1801998968 |
| 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