DENNIS WILLIAMS MFT
DENNIS WILLIAMS MFT is an organization registered with the National Plan and Provider Enumeration System (NPPES) under NPI 1003549635, based in Fullerton, CA. It is classified under Counseling Psychologist.
Getting there
Here is what surrounds this office in Fullerton, based on OpenStreetMap data collected Oct 5, 2026. Parking is available about 0.38 mi away at Fullerton College Student Parking Structure. There is EV charging 0.46 mi from the office — useful if you are driving in from out of town. The nearest transit stop is 428 ft away, served by Commonwealth-Lawrence. If you arrive early, there is a coffee shop 0.48 mi away.
Getting here and what is nearby
Transit Commonwealth-Balcom 249 ft ~1 min
Transit Commonwealth-Balcom 267 ft ~2 min
Transit Commonwealth-Lawrence 428 ft ~2 min
Parking 777 ft ~3 min
Parking Fullerton College Staff Parkinglot 833 ft ~4 min
Restaurant Don Carlos 0.21 mi ~5 min
300 East Commonwealth Avenue, Fullerton 92832
Restaurant Taco Bell 0.21 mi ~5 min
301 East Commonwealth Avenue, Fullerton 92832
Mo-Th 07:00-24:00; Fr-Sa 07:00-01:00; Su 07:00-24:00
Restaurant Khan Saab Desi Craft Kitchen 0.26 mi ~6 min
229 East Commonwealth Avenue, Fullerton 92832
Mo-Fr 16:00-23:00;Sa-Su 14:00-23:00
Coffee Santa Fe Express Cafe 0.37 mi ~8 min
Convenience King's Group Smoke 0.38 mi ~8 min
Parking Fullerton College Student Parking Structure 0.38 mi ~8 min
230 East Chapman Avenue
Coffee It's Boba Time 0.39 mi ~8 min
EV charging 0.46 mi ~10 min
Coffee The Night Owl 0.48 mi ~10 min
Gas station 76 0.50 mi ~10 min
Gas station 76 0.50 mi ~11 min
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
NPPES does not list a state licence number for this record. That is not unusual — organizations and some provider types are not required to file one. Verify current licensure with the relevant state board before care.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Counseling covers
A psychologist who specializes in general practice and health service. It focuses on how people function both personally and in their relationships at all ages. Counseling psychology addresses the emotional, social, work, school and physical health concerns people may have at different stages in their lives, focusing on typical life stresses and more severe issues with which people may struggle as individuals and as a part of families, groups and organizations. Counseling psychologists help people with physical, emotional and mental health issues improve their sense of well-being, alleviate feelings of distress and resolve crises. They also provide assessment, diagnosis, and treatment of more severe psychological symptoms. NUCC Health Care Provider Taxonomy, code 103TC1900X
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-2 identifies an organization — a clinic, hospital, group practice, laboratory, or supplier. Individual clinicians working there hold their own NPI-1 numbers separately, so a bill may reference both.
| NPI | 1003549635 valid check digit |
|---|---|
| Entity type | Organization (NPI-2) |
| Enumeration date | Jul 1, 2022 |
| Last updated | Jul 1, 2022 |
| Status | Active |
| Practice address |
440 E COMMONWEALTH AVE STE 205 Fullerton, CA 92832 (714) 234-0906 |
| Other identifiers |
1043715840
· Other (CA) |
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 | 0 | 0 | 3 | 5 | 4 | 9 | 6 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 1 | 4 | 9 | 6 | 6 |
Sum = 55 · next multiple of 10 = 60 · check digit = 5 · actual last digit = 5
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.