Michael Chang, D.O.
Michael Chang, D.O. is a Pain Medicine (Physical Medicine & Rehabilitation) Physician in Walnut Creek, CA, registered under NPI 1205934262.
Getting there
The practice address on file is 2405 SHADELANDS DR, Walnut Creek, CA 94598. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 20A8518 | CA | Pain Medicine (Physical Medicine &… primary |
This provider holds licence 20A8518 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Physical Medicine And Rehabilitation
- PAC ID
- 4688774664
Medicare enrolment is recorded as approved under the provider type Practitioner - Physical Medicine And Rehabilitation. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Pain Medicine covers
A physician who provides a high level of care, either as a primary physician or consultant, for patients experiencing problems with acute, chronic or cancer pain in both hospital and ambulatory settings. Patient care needs may also be coordinated with other specialists. NUCC Health Care Provider Taxonomy, code 2081P2900X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1205934262 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 20, 2006 |
| Last updated | Nov 7, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | D.O. |
| Practice address |
2405 SHADELANDS DR Walnut Creek, CA 94598 (925) 939-8585 Fax (925) 933-2709 |
| Mailing address |
PO BOX 31396 Walnut Creek, CA 94598 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 2 | 0 | 5 | 9 | 3 | 4 | 2 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 0 | 5 | 9 | 3 | 8 | 2 | 3 |
Sum = 58 · next multiple of 10 = 60 · check digit = 2 · actual last digit = 2
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.