Marilyn Schwartz, PH.D.
Marilyn Schwartz, PH.D. is a Psychologist in Washington, DC, registered under NPI 1124249537. This provider registers 6 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 1350 CONNECTICUT AVE NW, Washington, DC 20036. 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 |
|---|---|---|
| 803 | DC | Psychologist primary |
| 803 | DC | Adult Development & Aging Psychologist |
| 803 | DC | Cognitive & Behavioral Psychologist |
| 803 | DC | Clinical Psychologist |
| 803 | DC | Family Psychologist |
| 803 | DC | Group Psychotherapy Psychologist |
This provider holds licence 803 issued in DC. 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
All registered taxonomy codes
This provider registers 6 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 103T00000X | Psychologist | 803 | DC | primary |
| 103TA0700X | Adult Development & Aging Psychologist Adult Development & Aging | 803 | DC | |
| 103TB0200X | Cognitive & Behavioral Psychologist Cognitive & Behavioral | 803 | DC | |
| 103TC0700X | Clinical Psychologist Clinical | 803 | DC | |
| 103TF0000X | Family Psychologist Family | 803 | DC | |
| 103TP2701X | Group Psychotherapy Psychologist Group Psychotherapy | 803 | DC |
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 | 1124249537 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 1, 2007 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | PH.D. |
| Practice address |
1350 CONNECTICUT AVE NW Washington, DC 20036 (202) 331-3319 |
| Mailing address |
5008 LOWELL ST NW Washington, DC 20016 |
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 | 2 | 4 | 2 | 4 | 9 | 5 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 4 | 4 | 4 | 4 | 9 | 5 | 6 |
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.