There may be medical reasons why circumcision were necessary such as using the foreskin as a skin graft to another location on your baby's body. This is very rare and the circumcision would not be done at birth.
Many insurances no longer cover the costs of circumcision. Their reasoning is that, unless there are medical reasons, it is a cosmetic surgery. This means that parents must pay for the circumcision out of their own pockets. Be sure to check with your insurance company on what you would pay out of pocket should you decide on this surgery for your son.
Some parents wonder about news articles stating that a circumcision can prevent all sorts of aliments. The AAP found these studies to be medically flawed in it's 2006 statement, but says now that there may be health benefits for newborns later in life. Opponents of circumcision say that these studies are done in developing countries and don't translate well to the US.
CIRCUMCISION, TASK FORCE ON. (2012). Circumcision Policy Statement. Pediatrics. doi: 10.1542/peds.2012-1989
Circumcision Policy Statement -- Task Force on Circumcision 103 (3): 686 -- AAP Policy