Quick answers
- Does Welby D. Nielsen accept Medicare assignment?
- Yes. Medicare's clinician data says Welby D. Nielsen 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 Welby D. Nielsen's NPI number?
- 1962611947. 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 Welby D. Nielsen is enrolled with Medicare (CMS data updated October 2, 2026).
- 1039 Murray Ave, Suite 220San Luis Obispo, CA 93405 (855) 501‑1004
- 2561 California Park Dr, Suite 300Chico, CA 95928 (855) 501‑1004
Group practices
Medicare enrollment lists Welby D. Nielsen as a member of this group (CMS data updated October 2, 2026).
- Mark David Levine MD Professional Corporation181 clinicians in the group
Specialties
- Psychiatryprimary
Other psychiatrists in San Luis Obispo
Clinicians with the same Medicare primary specialty in San Luis Obispo, CA — not a recommendation.
Other clinicians in Mark David Levine MD Professional Corporation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | University Of Arizona College Of Medicine |
| Graduation year | 2005 (21 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1962611947 |
| 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