I live in CT and got into an acc. in MA. The other driver was at fault.

This is a conflict of laws issue.  Many states follow the restatement, which says follow the law of the situs of the accident (most significant relationship test).  The test has something like six factors.  Where you bring an action is based on other issues: location of defendant usually.  Consult with an attorney in your state first.  try www.attorneypages.com.   Also look at the items below.  It seems most likely you will have to file in Massachusetts and most likely Massachusetts law would apply.

Sec. 52-59b.

Jurisdiction of courts over nonresidents and foreign partnerships. Service of process.

• As to a cause of action arising from any of the acts enumerated in this section, a court may exercise personal jurisdiction over any nonresident individual, or foreign partnership, or his or its executor or administrator, who in person or through an agent:
  1. Transacts any business within the state; or
  2. commits a tortuous act within the state, except as to a cause of action for defamation of character arising from the act; or
  3. commits a tortuous act outside the state causing injury to person or property within the state, except as to a cause of action for defamation of character arising from the act, if he 1. regularly does or solicits business, or engages in any other persistent course of conduct, or derives substantial revenue from goods used or consumed or services rendered, in the state, or 2. expects or should reasonably expect the act to have consequences in the state and derives substantial revenue from interstate or international commerce; or
• owns, uses or possesses any real property situated within the state.
  1. Where personal jurisdiction is based solely upon this section, an appearance does not confer personal jurisdiction with respect to causes of action not arising from an act enumerated in this section.
  2. Any nonresident individual, or foreign partnership, or his or its executor or administrator, over whom a court may exercise personal jurisdiction, as provided in subsection (a), shall be deemed to have appointed the Secretary of the State as its attorney and to have agreed that any process in any civil action brought against the nonresident individual or foreign partnership, or his or its executor or administrator, may be served upon the Secretary of the State and shall have the same validity as if served upon the nonresident individual or foreign partnership personally. The process shall be served by the officer to whom the same is directed upon the secretary by leaving with or at the office of the secretary, at least twelve days before the return day of such process, a true and attested copy thereof, and by sending to the defendant at his last-known address, by registered or certified mail, postage prepaid, a like true and attested copy with an endorsement thereon of the service upon the secretary. The officer serving such process upon the secretary shall leave with the secretary, at the time of service, a fee of twenty-five dollars, which fee shall be taxed in favor of the plaintiff in his costs if he prevails in any such action. The Secretary of the State shall keep a record of each such process and the day and hour of service.

Sec. 52-62.

Service upon nonresident in action for negligent operation of motor vehicle.

• Any nonresident of this state who causes a motor vehicle to be used or operated upon any public highway or elsewhere in this state shall be deemed to have appointed the Commissioner of Motor Vehicles as his attorney and to have agreed that any process in any civil action brought against him on account of any claim for damages resulting from the alleged negligence of the nonresident or his agent or servant in the use or operation of any motor vehicle upon any public highway or elsewhere in this state may be served upon the commissioner and shall have the same validity as if served upon the nonresident personally.
• The death of such a nonresident, whether before or after the commencement of a civil action, shall not operate to revoke the appointment by the nonresident of the Commissioner of Motor Vehicles as his attorney for service of process. If the process is served upon the Commissioner of Motor Vehicles and a true and attested copy thereof is sent to the administrator, executor or other legal representative of the deceased nonresident in accordance with the provisions of this section, the service shall have the same validity as if made upon the administrator, executor or legal representative personally.
• Process in such a civil action against a nonresident shall be served by the officer to whom the process is directed upon the Commissioner of Motor Vehicles by leaving with or at the office of the commissioner, at least twelve days before the return day of the process, a true and attested copy thereof, and by sending to the defendant or his administrator, executor or other legal representative, by registered or certified mail, postage prepaid, a like true and attested copy, with an endorsement thereon of the service upon the commissioner, addressed to the defendant or representative at his last-known address. The officer serving the process upon the Commissioner of Motor Vehicles shall leave with the commissioner, at the time of service, a fee of five dollars, which fee shall be taxed in favor of the plaintiff in his costs if he prevails in the action. The Commissioner of Motor Vehicles shall keep a record of each such process and the day and hour of service.
• For the purposes of this section, the term “nonresident” includes a person who is a resident of this state at the time a cause of action arises and who subsequently moves to another jurisdiction