EDIT: I found the answer. Apparently you can be legally female in Mass as long as a doctor or therapist provides proof for you.
http://www.masstpc.org/projects/rmv-changes.shtml (http://www.masstpc.org/projects/rmv-changes.shtml)
If it's SRS, it's SRS. I might be mistaken, but I'm almost sure it refers to a complete SRS, excluding orchiectomy.