William Percy, PHD, LP, LMFT
William Percy, PHD, LP, LMFT is a Marriage & Family Therapist in Minneapolis, MN, registered under NPI 1881643518. 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 1409 WILLOW ST SUITE 220, Minneapolis, MN 55403. 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 |
|---|---|---|
| LP184 | MN | Psychologist |
| 78 | MN | Marriage & Family Therapist primary |
This provider holds licence LP184 issued in MN. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
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 Marriage & Family Therapist covers
A marriage and family therapist is a person with a master's degree in marriage and family therapy, or a master's or doctoral degree in a related mental health field with substantially equivalent coursework in marriage and family therapy, who receives supervised clinical experience, or a person who meets the state requirements to practice as a marriage and family therapist. A marriage and family therapist treats mental and emotional disorders within the context of marriage and family systems. A marriage and family therapist provides mental health and counseling services to individuals, couples, families, and groups. NUCC Health Care Provider Taxonomy, code 106H00000X
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 | LP184 | MN | |
| 106H00000X | Marriage & Family Therapist | 78 | MN | 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 | 1881643518 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 9, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | PHD, LP, LMFT |
| Practice address |
1409 WILLOW ST SUITE 220 Minneapolis, MN 55403 (612) 819-2311 Fax (612) 870-4542 |
| Mailing address |
111 E FRANKLIN AVE #319 Minneapolis, MN 55404 |
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 | 8 | 8 | 1 | 6 | 4 | 3 | 5 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 7 | 1 | 3 | 4 | 6 | 5 | 2 |
Sum = 62 · next multiple of 10 = 70 · check digit = 8 · actual last digit = 8
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.