Doctor profile · Federal record

Dr. Michael Halassa, MBBS, PHD

Psychiatry Physician (CMS: Psychiatry) · Boston, MA

  • NPI 1811124639
  • Accepts Medicare
  • MIPS 88.6 / 100 · 2023
  • 22 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

Operates at 3 locations .

NPPES Updated May 11, 2026
Primary practice
Massachusetts General Hospital, 55 Fruit Street
Boston, MA 02114
(617) 726-2066
Additional location
200 May St
South Attleboro, MA 027035520
(508) 761-8500
Additional location
386 Stanley St
Fall River, MA 027206009
(508) 679-5222
fax (508) 673-3182

Credentials & registration

NPPES · NUCC
NPI registered
June 2009 — 17 yrs on file
Profile last updated
September 23, 2025
Year of graduation
2004 — 22 yrs since
Specialty taxonomy
2084P0800X — NUCC code
State license (1)
Massachusetts #L-240799

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1811124639. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
244
Distinct HCPCS
1
Medicare allowed
$10,986
HCPCS Description Services Patients Avg allowed
99231 Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 244 37 $45

In context: peer comparison

Among 128 peers in Boston Psychiatry Physician, average services per provider: 69. This provider delivers 3.5× the peer median.

Frequently asked questions

Auto-generated from federal data
What is Dr. Michael Halassa's medical specialty?
Dr. Michael Halassa practices Psychiatry Physician in Boston, MA.
Where does Dr. Michael Halassa practice?
Dr. Michael Halassa practices at Massachusetts General Hospital, Boston, MA 02114. Office phone: 6177262066.
What is Dr. Michael Halassa's NPI?
Dr. Michael Halassa's National Provider Identifier (NPI) is 1811124639, issued by NPPES.
Does Dr. Michael Halassa accept Medicare assignment?
Yes. Dr. Michael Halassa accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Michael Halassa commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with straightforward or low level of medical decision making (HCPCS 99231). Source: CMS Medicare Physician & Other Practitioners file.