I waited to change my gender marker on my documentation and identification until I had received my name legal name change. I did this because having to change my IDs again and request yet another social security card, etc., would be double the work and cost extra money.
I changed my gender marker in the State of New York, which requires a letter from your surgeon stating that they have completed irreversible sex reassignment surgery and they attest that this gender change is warranted. They don’t require the surgeon specify which procedure – so most guys are able to get this done with a letter from whoever completes their top surgery, depending on the surgeon. It is a good idea to ask if surgeons provide this letter when researching potential surgeons for chest surgery, as some may not provide this letter, although most of them do.
Both the DMV and the Social Security office require the surgeon’s letter on their original letterhead. If you are changing both your name and gender marker, make sure you take your name change order as well.
If you are planning on changing your gender marker:
I would recommend starting a folder for all your paperwork regarding your name and gender marker change, whatever is relevant for you. In this folder, keep all original copies of everything, and when you go to a bank, the DMV, or any institution where you need to change your name and gender, make sure you carry this folder. I have had to go back to the house several times because I didn’t have something I needed.