William Maronn, LICSW
William Maronn, LICSW is a provider specialising in Clinical Social Worker in Lexington, MA, registered under NPI 1003617119. 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 Lexington, based on OpenStreetMap data collected Oct 10, 2026. Parking is available about 636 ft away. The nearest transit stop is 231 ft away, served by 57 Bedford St. A pharmacy sits 330 ft from the entrance (Walgreens), which helps if you leave with a prescription. If you arrive early, there is a coffee shop 0.46 mi away.
Getting here and what is nearby
Transit Bedford Street @ Lois Lane 161 ft ~1 min
Coffee Starbucks 167 ft ~1 min
Transit Opp 57 Bedford St 194 ft ~1 min
Transit 57 Bedford St 231 ft ~1 min
Pharmacy Walgreens 330 ft ~2 min
Parking 440 ft ~2 min
Parking 550 ft ~3 min
Restaurant Qdoba 550 ft ~3 min
Parking 636 ft ~3 min
Gas station Gulf 690 ft ~3 min
Grocery Stop & Shop 728 ft ~3 min
36 Bedford Street, Lexington 02420
Mo-Sa 07:00-22:00; Su 07:00-21:00
Hotel The Inn at Hastings Park 0.34 mi ~7 min
Restaurant Alexander's Pizza 0.40 mi ~8 min
172;174;176;178;180;182;184 Bedford Street, Lexington 02420
Mo-Sa 10:00-22:00
Restaurant Royal India Bistro 0.44 mi ~9 min
Coffee Via Lago (Closed) 0.45 mi ~9 min
Coffee Sweet Thyme Bakery 0.46 mi ~10 min
1837 Massachusetts Avenue, Lexington 02420
Mo-Tu off; We-Su 12:00-17:30
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 |
|---|---|---|
| LICSW1140764 | MA | Clinical Social Worker primary |
This provider holds licence LICSW1140764 issued in MA. 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 Social Worker
- PAC ID
- 9335645068
- Enrollment ID
- I20251001004212
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Social Worker. 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 social worker who holds a master's or doctoral degree in social work from an accredited school of social work in addition to at least two years of post-master's supervised experience in a clinical setting. The social worker must be licensed, certified, or registered at the clinical level in the jurisdiction of practice. A clinical social worker provides direct services, including interventions focused on interpersonal interactions, intrapsychic dynamics, and life management issues. Clinical social work services are based on bio-psychosocial perspectives. Services consist of assessment, diagnosis, treatment (including psychotherapy and counseling), client-centered advocacy, consultation, evaluation, and prevention of mental illness, emotional, or behavioral disturbances. NUCC Health Care Provider Taxonomy, code 1041C0700X
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 | 1003617119 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 24, 2025 |
| Last updated | Jun 2, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | LICSW |
| Practice address |
76 BEDFORD ST STE 22 Lexington, MA 02420 (617) 866-0810 |
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 | 6 | 1 | 7 | 1 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 3 | 1 | 5 | 1 | 2 |
Sum = 41 · next multiple of 10 = 50 · check digit = 9 · actual last digit = 9
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.