Just about all types of retirement accounts are considered part of the marital estate in MA, including IRAs, Keoghs, 401 k plans, and 403 k plans, regardless of who is named on the plan.  There are a few types of retirement funds that are not considered part of the marital estate, including railroad retirement benefits and social security benefits.  Massachusetts General Law Chapter 208, Section 34 states in relevant part:

In addition to or in lieu of a judgment to pay alimony, the court may assign to either husband or wife all or any part of the estate of the other, including but not limited to, all vested and nonvested benefits, rights and funds accrued during the marriage and which shall include, but not be limited to, retirement benefits, military retirement benefits if qualified under and to the extent provided by federal law, pension, profit-sharing, annuity, deferred compensation and insurance.

Typically, either on their own or through attorneys, parties to a Massachusetts divorce action will settle the distribution of marital assets, including pension funds, rather than letting a court decide.  Massachusetts courts have a lot of discretion when it comes to the division of property, and each case will be considered on its own facts, so it is impossible to tell how the court will divide your property.  The goal is always equity. Here is what the law (Section 34, again) says:

 . . . in fixing the nature and value of the property, if any, to be so assigned, the court, after hearing the witnesses, if any, of each party, shall consider the length of the marriage, the conduct of the parties during the marriage, the age, health, station, occupation, amount and sources of income, vocational skills, employability, estate, liabilities and needs of each of the parties and the opportunity of each for future acquisition of capital assets and income. In fixing the nature and value of the property to be so assigned, the court shall also consider the present and future needs of the dependent children of the marriage. The court may also consider the contribution of each of the parties in the acquisition, preservation or appreciation in value of their respective estates and the contribution of each of the parties as a homemaker to the family unit.

In practice, MA divorce attorneys  often offer this general rule:  The longer you and your spouse were married, the more likely it is that all marital assets will be divided equally.  In cases where the couple has only been married a short time, it is more common for the court to try to 'turn back the clock' and place the parties in the position they were in before the marriage.

Hope all that helps.