Can I Get a Breast Augmentation at 16 Years a Old ?

I would strongely advice you to wait until your breasts have fully developed. With that said, I have performed surgery on 16 year olds who suffer from severe breast asymmetry and are ridiculed at school.  This is a very different picture however. These patients are accompanied by their parents and a full history is obtained to see whether surgery at this age will be beneficial to the patient.   If at 19 years of age or so your breasts have fully developed and you still want surgery, then consult a Board Certified Plastic Surgeon.

While reconstructive plastic surgery is sometimes appropriate for girls your age, breast augmentations are generally not appropriate.

Give your mind and body time to continue maturing. As many of the surgeons here have already noted, breast development can continue into the late teens and early twenties so while you feel you need an augmentation now, you may also change your mind later. You definitely don't want to go through breast augmentation surgery now only to go through a removal surgery a few years from now.

Unfortunately, unless you have a congential/developmental deformity, you need to wait until the age of 18.  If you are considering silicone gel implants, then you will need to wait till you are 22.  As others have stated, your breast may still undergo changes and growth even into your 20's. 
 

breast surgery can be done for developemental problems

these include severe unevenness,  tubular deformity

it is generally best to wait until at least 18 otherwise.

hormones change, growth can happen late even up to early 20's

Not a good idea to have breast augmentation at your age.

However,  if you feel that you are dealing with a congenital problem,  it will behoove you to meet with well experienced board certified plastic surgeons.

Best wishes.