Katrina Colby, PHD
Katrina Colby, PHD is a Rehabilitation Psychologist in Bethesda, MD, registered under NPI 1164805594. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. 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 8901 ROCKVILLE PIKE, Bethesda, MD 20889. 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 |
|---|---|---|
| 07571 | MD | Rehabilitation Psychologist primary |
| 07571 | MD | Clinical Psychologist |
This provider holds licence 07571 issued in MD. 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
- Order And Referring Only - Clinical Psychologist
- PAC ID
- 1254828023
- Enrollment ID
- I20251015000871
Medicare enrolment is recorded as approved under the provider type Order And Referring Only - Clinical Psychologist. 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.
What Rehabilitation covers
A psychologist who specializes in the study and application of psychological principles on behalf of persons who have disability due to injury or illness. Rehabilitation psychologists, often within teams, assess and treat cognitive, emotional, and functional difficulties, and help people to overcome barriers to participation in life activities. Rehabilitation psychologists are involved in practice, research, and advocacy, with the broad goal of fostering independence and opportunity for people with disabilities. NUCC Health Care Provider Taxonomy, code 103TR0400X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 103TR0400X | Rehabilitation Psychologist Rehabilitation | 07571 | MD | primary |
| 103TC0700X | Clinical Psychologist Clinical | 07571 | MD |
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 | 1164805594 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 2, 2015 |
| Last updated | Apr 8, 2026 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | PHD |
| Practice address |
8901 ROCKVILLE PIKE Bethesda, MD 20889 (301) 400-2031 |
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 | 8 | 0 | 5 | 5 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 3 | 4 | 7 | 0 | 1 | 5 | 9 |
Sum = 56 · next multiple of 10 = 60 · check digit = 4 · actual last digit = 4
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.