Gareth Marsh, DO
NPI 1124558531 · Psychiatry Physician · Columbia, MO
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gareth Marsh, DO is a Psychiatry Physician provider in Columbia, MO (NPI 1124558531).
Provider details
- NPI number
- 1124558531
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Male
- Sole proprietor
- No
- License
- 2017020205 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
9 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
161 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 146 | $90 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 15 | $61 |
Typical Medicare-allowed amounts for these services range $61–$90 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 43 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Lorazepam | 137 | 32 |
| Buspirone Hcl | 132 | 30 |
| Trazodone Hcl | 119 | 31 |
| Desvenlafaxine Succinatebrand: Desvenlafaxine Succinate Er | 103 | 20 |
| Lamotrigine | 95 | 25 |
| Vortioxetine Hydrobromidebrand: Trintellix | 93 | 14 |
| Gabapentin | 90 | 17 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2017-06-18
- Last updated
- 2017-06-18
Frequently asked questions
- What is Gareth Marsh's NPI number?
- Gareth Marsh's National Provider Identifier (NPI) is 1124558531, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gareth Marsh's specialty?
- Gareth Marsh is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Gareth Marsh located?
- Gareth Marsh's practice location on file with NPPES is 1 Hospital Dr, Columbia, MO 65212-1000.
- What is Gareth Marsh's phone number?
- The practice phone number listed in the NPPES registry for Gareth Marsh is (573) 882-8907.
- Does Gareth Marsh accept Medicare?
- Gareth Marsh is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gareth Marsh's NPI active?
- Yes — Gareth Marsh's NPI (1124558531) is active in the NPPES registry as of the last update on 2017-06-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.