Quick answers
- Does Donald A. Underwood accept Medicare assignment?
- Yes. Medicare's clinician data says Donald A. Underwood accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- What is Donald A. Underwood's NPI number?
- 1598861817. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Donald A. Underwood is enrolled with Medicare (CMS data updated October 2, 2026).
- 665 N D StSan Bernadino, CA 92401 (909) 708‑8158
Group practices
Medicare enrollment lists Donald A. Underwood as a member of this group (CMS data updated October 2, 2026).
- Inland Behavioral and Health Services Inc9 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Other clinicians in Inland Behavioral and Health Services Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | College Of Medicine And Surgery |
| Graduation year | 1974 (52 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1598861817 |
| 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
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- 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