Mark Skellie, PSY.D.
Mark Skellie, PSY.D. is a Psychologist in Atlanta, GA, registered under NPI 1265733851. 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 1000 JOHNSON FERRY RD, Atlanta, GA 30342. 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 |
|---|---|---|
| PS-T001180 | GA | Psychologist primary |
| 1190 | LA | Clinical Psychologist |
Licences are recorded in 2 states: GA, LA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Clinical Psychologist
- PAC ID
- 6204091382
Enrolled in Medicare 2 times, across 2 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Louisiana | I20120625000224 | Practitioner - Clinical Psychologist |
| Georgia | I20260210003412 | Practitioner - Clinical Psychologist |
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Psychologist. There are 2 separate enrolment records across 2 states (LA, GA). 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: Georgia and Louisiana. The practice address on file is in Atlanta, GA, 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 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 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 103T00000X | Psychologist | PS-T001180 | GA | primary |
| 103TC0700X | Clinical Psychologist Clinical | 1190 | LA |
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 | 1265733851 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 12, 2010 |
| Last updated | Dec 15, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | PSY.D. |
| Practice address |
1000 JOHNSON FERRY RD Atlanta, GA 30342 (404) 851-8000 Fax (404) 303-3759 |
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 | 6 | 5 | 7 | 3 | 3 | 8 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 3 | 5 | 5 | 3 | 6 | 8 | 1 |
Sum = 59 · next multiple of 10 = 60 · 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.