Cosmetic surgery, in its true sense, is an elective procedure that is performed to reshape or enhance body parts a patient may find unflattering. Since cosmetic surgery has an intrinsic aesthetic intent, it is usually not covered by health insurance. The argument put forth by insurance firms is that a person can very well do without cosmetic surgery, and the procedure is used for mere beautification instead of being a life saving surgery. On the other hand, reconstructive surgery is generally covered by health insurance, though the extent of coverage may vary a lot from one case to another.
In many ways, the answer to the insurance question lies in discerning whether the plastic surgery procedure is cosmetic or reconstructive. For instance, abdominoplasty (or tummy tuck), when performed on an obese patient to guard the patient against heart problems, is eligible for health insurance. Breast reduction surgery, when carried out with the intent of reducing weight of the breasts to curtail orthopedic pain, is typically covered by health insurance. On the other hand, breast implants or augmentations are performed with the aesthetic aspect in mind and, therefore, don't normally qualify for an insurance.
There is a fine line dividing the two categories of plastic surgery, namely cosmetic and reconstructive surgery, as far as eligibility for insurance is concerned. For instance, eyelid surgery, when performed to attain an aesthetic enhancement is considered cosmetic and ineligible for insurance. The same procedure may be covered by insurance if the eyelids are drooping to the extent of obscuring a patient's vision. The hard fact remains that most of the plastic surgery procedures are performed with an aesthetical intent, in order to enhance alluring portions of the body.
To summarise, plastic surgery that is performed to improve function instead of aesthetics is normally eligible for an insurance cover. However, it's best to discuss your case with an insurance agent, in order to determine if you are eligible for an insurance cover.