David Callahan, PH.D.
David Callahan, PH.D. is a Psychologist in Sandwich, MA, registered under NPI 1205865797.
Getting there
The practice address on file is 449 ROUTE 130 SUITE 12, Sandwich, MA 02563. 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 |
|---|---|---|
| 4061 | MA | Psychologist primary |
This provider holds licence 4061 issued in MA. 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 Psychologist covers
A psychologist is an individual who is licensed to practice psychology which is defined as the observation, description, evaluation, interpretation, and modification of human behavior by the application of psychological principles, methods, and procedures, for the purpose of preventing or eliminating symptomatic, maladaptive, or undesired behavior and of enhancing interpersonal relationships, work and life adjustment, personal effectiveness, behavioral health, and mental health. The practice of psychology includes, but is not limited to, psychological testing and the evaluation or assessment of personal characteristics, such as intelligence, personality, abilities, interests, aptitudes, and neuropsychological functioning; counseling, psychoanalysis, psychotherapy, hypnosis, biofeedback, and behavior analysis and therapy; diagnosis and treatment of mental and emotional disorder or disability, alcoholism and substance abuse, disorders of habit or conduct, as well as of the psychological aspects of physical illness, accident, injury, or disability; and psycheducational evaluation, therapy, remediation, and consultation. Psychological services may be rendered to individuals, families, groups and the public. NUCC Health Care Provider Taxonomy, code 103T00000X
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 | 1205865797 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 30, 2006 |
| Last updated | Jan 30, 2013 |
| Status | Active |
| Sole proprietor | No |
| Credential | PH.D. |
| Practice address |
449 ROUTE 130 SUITE 12 Sandwich, MA 02563 (508) 888-7744 Fax (508) 888-7725 |
| Mailing address |
P.O. BOX 1037 Sandwich, MA 02563 |
| Other identifiers |
0516821
· Medicaid (MA) |
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 | 2 | 0 | 5 | 8 | 6 | 5 | 7 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 0 | 5 | 7 | 6 | 1 | 7 | 9 |
Sum = 63 · next multiple of 10 = 70 · check digit = 7 · actual last digit = 7
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.