Steven Callahan, PH.D.
Steven Callahan, PH.D. is a Clinical Psychologist in Houston, TX, registered under NPI 1275677643. 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 2450 FONDREN RD STE 312, Houston, TX 77063. 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 |
|---|---|---|
| 22630 | TX | Psychologist |
| 22630 | TX | Clinical Psychologist primary |
This provider holds licence 22630 issued in TX. 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 - Clinical Psychologist
- PAC ID
- 3870407513
Enrolled in Medicare 11 times, across 11 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Texas | I20101118001277 | Practitioner - Clinical Psychologist |
| Alabama | I20240411001206 | Practitioner - Clinical Psychologist |
| Indiana | I20240412003821 | Practitioner - Clinical Psychologist |
| Florida | I20240501001362 | Practitioner - Clinical Psychologist |
| Colorado | I20240523001364 | Practitioner - Clinical Psychologist |
| Kentucky | I20240529001556 | Practitioner - Clinical Psychologist |
| Ohio | I20240529003484 | Practitioner - Clinical Psychologist |
| Georgia | I20240621001995 | Practitioner - Clinical Psychologist |
| Nebraska | I20241210003127 | Practitioner - Clinical Psychologist |
| Oklahoma | I20250204001447 | Practitioner - Clinical Psychologist |
| Arizona | I20250327002615 | Practitioner - Clinical Psychologist |
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Psychologist. There are 11 separate enrolment records across 11 states (TX, AL, IN, FL, CO, KY, OH, GA, NE, OK, AZ). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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 Clinical covers
A psychologist who provides continuing and comprehensive mental and behavioral health care for individuals and families; consultation to agencies and communities; training, education and supervision; and research-based practice. It is a specialty in breadth -- one that is broadly inclusive of severe psychopathology -- and marked by comprehensiveness and integration of knowledge and skill from a broad array of disciplines within and outside of psychology proper. The scope of clinical psychology encompasses all ages, multiple diversities and varied systems. NUCC Health Care Provider Taxonomy, code 103TC0700X
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 | |
|---|---|---|---|---|
| 103T00000X | Psychologist | 22630 | TX | |
| 103TC0700X | Clinical Psychologist Clinical | 22630 | TX | 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 | 1275677643 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Feb 17, 2007 |
| Last updated | Jul 6, 2026 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | PH.D. |
| Practice address |
2450 FONDREN RD STE 312 Houston, TX 77063 (713) 789-7560 Fax (713) 789-7351 |
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 | 7 | 5 | 6 | 7 | 7 | 6 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 5 | 5 | 3 | 7 | 5 | 6 | 8 |
Sum = 67 · next multiple of 10 = 70 · check digit = 3 · actual last digit = 3
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.