We are suppose to just be able to tell HR & that be that, they just need the birth date. We were told that by the HR lady & even the insurance booklet I read said we only needed the baby's birthdate to add him.
But turns out, last time around, we had 60 days to produce a social security number for him to actually add him to the policy to give him retroactive coverage from birth (we had a hospital birth, so the kooky change in info they wanted had nothing to do with where he was born, just your normal crap dealing with insurance). We can just go through HR to have them add the new baby or call our company, after a couple weeks we get a letter with a request for the SS # before they would allow DS to the policy.
I'd call insurance & ask how to add a baby to a policy, what info you need to provide, & if there is a time frame you have to do it all in to get retroactive coverage.