If you are undergoing reconstructive surgery following an accident or illness, breast implants may be covered by your insurance. If the implants are not intended to provide recovery from illness or injury, it is probably not covered by your insurance plan. To put this into a clearer perspective, think of it as the insurance being obligated to return you to your previous state of health as closely as possible, but they have no obligation to help you become a different person.
Even more, if you pay for the augmentation yourself, you may discover that your premiums increase or that the insurance will not cover future surgeries or removal if a problem comes up. For example, if you develop an infection from the surgery, or if the implants have to be taken out for some other reason, the insurance company may tell you that the implants are not part of your original policy, or are not considered an insured risk, even if the medical attention you require would have been covered under other circumstances.
Your medical insurance might cover breast reductions, but only if such a procedure can be shown to create a better state of health for you. Medical insurance is focused on improving the medical health of their customers, and rarely perceive implants as offering any sort of improvement. Even worse, you should consult your insurance before having the procedure to find out whether implants will have a negative effect on the rest of your coverage.