Mary Karlan, LCSW
Mary Karlan, LCSW is a provider specialising in Social Worker in Old Greenwich, CT, registered under NPI 1871976431. 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 177 SOUND BEACH AVE STE 6, Old Greenwich, CT 06870. 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 |
|---|---|---|
| 088338-1 | NY | Social Worker |
| 121299 | Clinical Social Worker | |
| 001369 | CT | Social Worker primary |
Licences are recorded in 2 states: NY, CT. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Clinical Social Worker
- PAC ID
- 8224311071
Enrolled in Medicare 5 times, across 5 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Connecticut | I20170202000023 | Practitioner - Clinical Social Worker |
| Massachusetts | I20210603002168 | Practitioner - Clinical Social Worker |
| New York | I20211005000151 | Practitioner - Clinical Social Worker |
| Florida | I20240116001658 | Practitioner - Clinical Social Worker |
| California | I20240412003586 | Practitioner - Clinical Social Worker |
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Social Worker. There are 5 separate enrolment records across 5 states (CT, MA, NY, FL, CA). 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.
Licensed in 2 states
This provider holds licences in 2 states: Connecticut and New York. The practice address on file is in Old Greenwich, CT, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Social Worker covers
A social worker is a person who is qualified by a Social Work degree, and licensed, certified or registered by the state as a social worker to practice within the scope of that license. A social worker provides assistance and counseling to clients and their families who are dealing with social, emotional and environmental problems. Social work services may be rendered to individuals, families, groups, and the public. NUCC Health Care Provider Taxonomy, code 104100000X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 104100000X | Social Worker | 088338-1 | NY | |
| 1041C0700X | Clinical Social Worker Clinical | 121299 | — | |
| 104100000X | Social Worker | 001369 | CT | 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 | 1871976431 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 1, 2015 |
| Last updated | Oct 22, 2020 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | LCSW |
| Practice address |
177 SOUND BEACH AVE STE 6 Old Greenwich, CT 06870 (203) 493-0937 |
| Other names |
Mary Karlan Doing Business As |
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 | 7 | 1 | 9 | 7 | 6 | 4 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 5 | 1 | 9 | 7 | 3 | 4 | 6 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
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.