Mark Deyab, LICSW
Mark Deyab, LICSW is a Mental Health Counselor in Waltham, MA, registered under NPI 1104907732.
Getting there
The practice address on file is 20 HOPE AVE G-05, Waltham, MA 02453. 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 |
|---|---|---|
| 111824 | MA | Mental Health Counselor primary |
This provider holds licence 111824 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
- 8921065368
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Social Worker. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Mental Health covers
Definition to come... NUCC Health Care Provider Taxonomy, code 101YM0800X
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 | 1104907732 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Oct 18, 2006 |
| Last updated | Mar 17, 2009 |
| Status | Active |
| Sole proprietor | No |
| Credential | LICSW |
| Practice address |
20 HOPE AVE G-05 Waltham, MA 02453 (781) 799-3949 Fax (781) 899-6386 |
| Mailing address |
34 WAREHAM ST APT. 1 Medford, MA 02155 |
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 | 1 | 0 | 4 | 9 | 0 | 7 | 7 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 0 | 4 | 9 | 0 | 5 | 7 | 6 |
Sum = 58 · next multiple of 10 = 60 · check digit = 2 · actual last digit = 2
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.