Can men get facial feminization surgery (FFS)? I'm 19 years old male, possibly trans.

FFS for males is not uncommon. Sometimes cisgender males with strong facial features use some of the FFS techniques in order to get softer and more harmonious features without getting to the point of looking feminine. Some cross dressing performers seek partial Facial Feminization Surgery that allows them to improve their performances without ceasing to present as men in their everyday's life.

HRT makes a very noticeable difference to the FFS results. 

The need for a therapist letter depends on each country's laws. In Argentina you don't need it. A declaration of self perceived gender from the patient is enough, as long as you are of age.

Many people come for facial feminization in parts.  They choose to have one area done, or another, and then consider doing more later.  There really is no significant advantage to having HRT before hand though it can provide some advantages for the skin quality.We can develop a customized plan for you that will work wonders.  Watch our videos to learn more.

Greetings thanks for your question
You can have now a FFS surgery., even men can have a FFS surgery.

I see men frequently who come in for parts of what I do in facial feminization such as setting back the brow bone, reducing the Adam's Apple, or making the nose smaller. I don't see a major difference the volume of the tissue int he face after HRT, but skin texture is usually improved. The main thing you would want to consider is whether or not you need anything done to your hairline. If you are not on HRT, it is likely that your hairline will continue to recede and thus making the hairline incision more visible later on. I usually do not make that incision in men unless they are on HRT. 
If you are trying to go through insurance for surgery and haven't been on hormones and aren't quite sure what you are going to do moving forward it is likely that you will be denied. I don't see any reason why a surgeon would tell you no if you wanted to start with a few of the above procedures I mentioned without being totally sure.  
The other thing you might want to consider starting is laser hair removal or electrolysis. It can be a lengthy process, and starting this wouldn't matter where you are in your transition.
Best of luck to you,
Sarah Saxon, MD