John Harris, M.D.
John Harris, M.D. is a Sleep Medicine (Otolaryngology) Physician in Concord, CA, registered under NPI 1164517421. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 2540 EAST ST, Concord, CA 94520. 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 |
|---|---|---|
| A20806 | CA | Sleep Medicine (Otolaryngology) Physician primary |
This provider holds licence A20806 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 - General Surgery
- PAC ID
- 8527194687
Medicare enrolment is recorded as approved under the provider type Practitioner - General Surgery. 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 Sleep Medicine covers
An Otolaryngologist who practices Sleep Medicine is certified in the subspecialty of sleep medicine and specializes in the clinical assessment, physiologic testing, diagnosis, management and prevention of sleep and circadian rhythm disorders. Sleep specialists treat patients of any age and use multidisciplinary approaches. Disorders managed by sleep specialists include, but are not limited to, sleep related breathing disorders, insomnia, hypersomnias, circadian rhythm sleep disorders, parasomnias and sleep related movement disorders. NUCC Health Care Provider Taxonomy, code 207YS0012X
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 | 1164517421 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Oct 4, 2006 |
| Last updated | Jul 8, 2007 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
2540 EAST ST Concord, CA 94520 (925) 753-1986 |
| Mailing address |
PO BOX 30012 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 | 1 | 6 | 4 | 5 | 1 | 7 | 4 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 3 | 4 | 1 | 1 | 5 | 4 | 4 |
Sum = 49 · next multiple of 10 = 50 · check digit = 1 · actual last digit = 1
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.