All PhD students are typically admitted with financial support. Support may be in the form of research assistantships or teaching assistantships. All forms of support include a tuition waiver, health insurance, and a competitive 9-month stipend.
The Clinical Psychology PhD Program has an extensive list of internal (UMass Boston) and external funding opportunities.
In addition to the resources listed there, here are some links to a few other major federal funding agencies:
The National Science Foundation: Specialized Information for Graduate Students
Here is a list of grant preparation resources and databases: