Michael Halassa, MBBS, PHD
NPI 1811124639 · Psychiatry Physician · Boston, MA
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael Halassa, MBBS, PHD is a Psychiatry Physician provider in Boston, MA (NPI 1811124639).
Provider details
- NPI number
- 1811124639
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- MBBS, PHD
- Sex
- Male
- Sole proprietor
- No
- License
- L-240799 (MA)
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
17 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
678 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) |
|---|---|---|
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 678 | $51 |
Typical Medicare-allowed amounts for these services range $51–$51 (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 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydroxyzine Pamoate | 23 | 18 |
| Gabapentin | 20 | 13 |
| Quetiapine Fumarate | 19 | — |
| Trazodone Hcl | 18 | 12 |
| Olanzapine | 16 | 11 |
| Clonazepam | 13 | — |
| Metformin Hcl | 12 | — |
Practice location
Mailing address
Additional practice locations (2)
- 386 Stanley StFall River, MA 02720-6009Phone: (508) 679-5222Fax: (508) 673-3182
- 200 May StSouth Attleboro, MA 02703-5520Phone: (508) 761-8500
Registry dates
- Enumerated
- 2009-06-19
- Last updated
- 2025-09-23
- Certified
- 2025-09-23
Frequently asked questions
- What is Michael Halassa's NPI number?
- Michael Halassa's National Provider Identifier (NPI) is 1811124639, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael Halassa's specialty?
- Michael Halassa is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Michael Halassa located?
- Michael Halassa's practice location on file with NPPES is Massachusetts General Hospital, Boston, MA 02114.
- What is Michael Halassa's phone number?
- The practice phone number listed in the NPPES registry for Michael Halassa is (617) 726-2066.
- Does Michael Halassa accept Medicare?
- Michael Halassa is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael Halassa's NPI active?
- Yes — Michael Halassa's NPI (1811124639) is active in the NPPES registry as of the last update on 2025-09-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.