I'm currently 20 years old and have severe MPB can I have a hair transplant at the age that I am? (photo)

Photos cannot determine if you would be a good candidate for surgery.  You need an examination and the doctor needs to understand your goals and expectations.
You need to have good communication with your doctor to understand what your end result will look like. 
Someone with your hair loss pattern may be perfectly happy with 1000 grafts, while others may not be happy even with over 3000 grafts.  You also have to realize one surgery may not be enough.  To add to the confusion, straight black hair on fair skin results in a thinner appearing outcome then someone with curly blond hair on fair skin.   I hope you can appreciate there are many factors to your end result than just a "number" of grafts.

From the one photo you show I don't know that I would call your hair loss "severe". 20 is very young for a hair transplant for a number of reasons.  At that age I would suggest maintenance/prevention first.  A consultation with a hair restoration specialist to discuss options such as minoxidil (Rogaine), laser, finasteride (Propecia) and platelet-rich plasma (PRP) would be beneficial.

A male who is 20 should not have a hair transplant or a hairline advancement surgery because if you do and develop balding behind the corrected hairline, you will not look normal. If you get a hairline advancement surgery you will see a scar. If you have a hair transplant before your balding pattern become evident, then you will be chasing hair transplants for the next decade. You should wait until your potential balding pattern becomes evident, which is 25 years of age. Build a Master Plan for your hair loss with a good doctor.