Gregory Houghton, M.D.
Gregory Houghton, M.D. is a Critical Care Medicine (Internal Medicine) Physician in Santa Rosa, CA, registered under NPI 1649489402. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 500 DOYLE PARK DR SUITE G04, Santa Rosa, CA 95405. 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 |
|---|---|---|
| 4301087479 | MI | Emergency Medicine Physician |
| A121765 | CA | Emergency Medicine Physician |
| A121765 | CA | Critical Care Medicine (Internal… primary |
Licences are recorded in 2 states: MI, CA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Critical Care (intensivists)
- PAC ID
- 6406027317
- Enrollment ID
- I20120918000502
Medicare enrolment is recorded as approved under the provider type Practitioner - Critical Care (intensivists). Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
Licensed in 2 states
This provider holds licences in 2 states: California and Michigan. The practice address on file is in Santa Rosa, CA, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- A121765
- Specialty
- Emergency Medicine Physician
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Critical Care Medicine covers
An internist who diagnoses, treats and supports patients with multiple organ dysfunction. This specialist may have administrative responsibilities for intensive care units and may also facilitate and coordinate patient care among the primary physician, the critical care staff and other specialists. NUCC Health Care Provider Taxonomy, code 207RC0200X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207P00000X | Emergency Medicine Physician | 4301087479 | MI | |
| 207P00000X | Emergency Medicine Physician | A121765 | CA | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | A121765 | CA | primary |
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 | 1649489402 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 21, 2007 |
| Last updated | Jan 23, 2025 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | M.D. |
| Practice address |
500 DOYLE PARK DR SUITE G04 Santa Rosa, CA 95405 (707) 303-8360 Fax (707) 303-8361 |
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 | 6 | 4 | 9 | 4 | 8 | 9 | 4 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 8 | 9 | 8 | 8 | 9 | 4 | 0 |
Sum = 78 · next multiple of 10 = 80 · 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.