Absolutely. The attorney/client relationship is based on a mutual and voluntary contractual relationship. The client can exit the relationship at any time. In fact, you are allowed to fire your Massachusetts personal lawyer at any time and you don't even need a reason for doing so.
I find that many people who call me and are interested in changing lawyers are doing so because they feel their lawyer is not communicating with them. If your lawyer is not calling you back and/or not keeping you updated on your case, you have the right to change lawyers. You may, however, be responsible for paying the lawyer back the expenses the lawyer put into the case.