Mary Williamson
Mary Williamson is a Professional Counselor in Saint Louis, MO, registered under NPI 1003130865. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
Here is what surrounds this office in Saint Louis, based on OpenStreetMap data collected Sep 7, 2026. Parking is available about 0.36 mi away. The nearest transit stop is 0.23 mi away, served by Clayton Transit Center. If you arrive early, there is a coffee shop 0.32 mi away.
Getting here and what is nearby
Coffee The Patio Café 184 ft ~1 min
Restaurant Café la Vie 207 ft ~1 min
7730 Bonhomme Avenue, St. Louis 63105
Mo-Fr 06:30-14:00, 16:00-22:30; Sa-Su 07:00-14:00, 16:00-22:30
Hotel Clayton Plaza Hotel 256 ft ~1 min
7750 Carondelet Avenue, Clayton 63105
Hotel Le Meridien St. Louis Clayton 287 ft ~2 min
Restaurant Plaza Grill 364 ft ~2 min
Mo-Fr 06:30-10:30; Sa,Su 07:30-10:30
Restaurant C.J. MUGG'S 707 ft ~3 min
Mo-Sa 11:00-01:30, Su 11:00-24:00
Convenience World News 1,019 ft ~4 min
Hotel AC Hotel 1,002 ft ~4 min
Coffee Starbucks 0.21 mi ~5 min
Parking 0.21 mi ~5 min
10 North Bemiston Avenue, Clayton 63105
Transit Clayton Transit Center 0.22 mi ~5 min
Transit Clayton Transit Center 0.23 mi ~5 min
Transit Clayton Transit Center 0.23 mi ~5 min
Parking 0.31 mi ~7 min
250 South Brentwood Boulevard, Clayton 63105
Coffee Starbucks 0.32 mi ~7 min
7645 Wydown Boulevard, Clayton 63105
Parking 0.36 mi ~8 min
602 South Hanley Road, Clayton 63105
Gas station BP 0.44 mi ~9 min
Su-Th 06:00-23:00; Fr,Sa 06:00-24:00
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 001837 | MO | Professional Counselor primary |
This provider holds licence 001837 issued in MO. 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 Professional covers
Definition to come... NUCC Health Care Provider Taxonomy, code 101YP2500X
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 | 1003130865 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 23, 2010 |
| Last updated | Mar 23, 2010 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Practice address |
7777 BONHOMME AVE SUITE 909 Saint Louis, MO 63105 (800) 356-0845 |
| Mailing address |
9735 LANDMARK PARKWAY DR SUITE 17 Saint Louis, MO 63127 |
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 | 1 | 3 | 0 | 8 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 2 | 3 | 0 | 8 | 3 |
Sum = 45 · next multiple of 10 = 50 · 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.