Marianne O'Leary, PH.D.
NPI 1720147374 · Psychologist · Ellicott City, MD
Enrolled with Medicare as Practitioner - Clinical Psychologist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Marianne O'Leary, PH.D. is a Psychologist provider in Ellicott City, MD (NPI 1720147374).
Provider details
- NPI number
- 1720147374
- Entity type
- Individual
- Primary specialty
- PsychologistBehavioral Health & Social Service Providers
- Credential
- PH.D.
- Sex
- Female
- Sole proprietor
- Yes
- License
- 03270 (MD)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
786 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Psychotherapy, 1 Hour90837 | 424 | $155 |
| Psychotherapy, 45 Minutes90834 | 321 | $105 |
| Psychotherapy, 30 Minutes90832 | 41 | $80 |
Typical Medicare-allowed amounts for these services range $80–$155 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-12-08
- Last updated
- 2007-07-08
Frequently asked questions
- What is Marianne O'Leary's NPI number?
- Marianne O'Leary's National Provider Identifier (NPI) is 1720147374, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Marianne O'Leary's specialty?
- Marianne O'Leary is listed in the NPPES registry with a primary specialty of Psychologist (Behavioral Health & Social Service Providers).
- Where is Marianne O'Leary located?
- Marianne O'Leary's practice location on file with NPPES is 3355 Saint Johns Ln, Ellicott City, MD 21042-2605.
- What is Marianne O'Leary's phone number?
- The practice phone number listed in the NPPES registry for Marianne O'Leary is (410) 465-5520.
- Does Marianne O'Leary accept Medicare?
- Marianne O'Leary is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Marianne O'Leary's NPI active?
- Yes — Marianne O'Leary's NPI (1720147374) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.