I currently hold an EEA Family permit. I have been married for 4
years and living in the UK for 3 years.

My husband wishes to move to the USA on his own for work reasons. I
wish to remain in the UK where I have a great job, bought a flat
and have a community of friends. My life is here.

If he permanently leaves the UK is it possible for me to retain the
right of residence? 

https://www.whatdotheyknow.com/request/retained_right_of_residence_for/new