| Baystate Administrative Services INC | Related tax-exempt org | Administrative services | MA | 222747685 |
| Baystate Franklin Medical Center | Related tax-exempt org | Hospital | MA | 042103575 |
| Baystate Health Foundation INC | Related tax-exempt org | Fundraising | MA | 043549011 |
| Baystate Medical Center INC | Related tax-exempt org | Acute care teaching hospital | MA | 042790311 |
| Baystate Noble Hospital Corporation | Related tax-exempt org | Hospital | MA | 222537423 |
| Baystate Total Home Care INC | Related tax-exempt org | Real estate and other | MA | 203260764 |
| Baystate WING Hospital Corporation | Related tax-exempt org | Hospital | MA | 222519813 |
| Health New England INC | Related tax-exempt org | HMO/insurance | MA | 042864973 |
| HNE of Connecticut INC | Related tax-exempt org | HMO/insurance | CT | 465190134 |
| Visiting Nurse ASSN and Hospice of Western New England INC | Related tax-exempt org | Homehealth and hospice care | MA | 042105803 |
| Amsurg BMC LLC | Related partnership | Medical services | TN | 843258572 |
| Baystate Health Urgent Care LLC | Related partnership | Urgent healthcare facility | MA | 384059312 |
| Baystate New England Orthopedic Surgeons Alliance LLC | Related partnership | Medical services | NC | 881824108 |
| Baystate Health Insurance Company LTD | Related taxable corporation/trust | Offshore captive insurance | — | 980421413 |
| HNE Advisory Services INC | Related taxable corporation/trust | Administrative services | MA | 043012347 |
| HNE Holding Corporation | Related taxable corporation/trust | Holding shares in subsidiary corporations | MA | 464620480 |
| HNE Insurance Company INC | Related taxable corporation/trust | Health INS SVCS for MASS medicare supplement members | MA | 454462433 |
| HNE Insurance Services INC | Related taxable corporation/trust | Ancillary insurance | MA | 043183019 |
| Ingraham Corporation | Related taxable corporation/trust | Health care and other business activities | MA | 043016257 |