Be prepared for her to be considered a late enrollee. Our insurance requires that newborns be added within 30 days of birth.
I assume the OP would be adding her at open enrollment time. No big deal.
OP, DS comes from a line of men with horrid baby teeth. Therefore, it wasn't a surprise when two of his teeth grew in yellow, turned brown, and started to disintegrate. From 1 until 2 years old we saw 3 dentists for him, trying to find someone sane and intelligent. Finally found one that met both criteria just before crunch time with the teeth.
I have my dental binder out...
1st dentist $75 was charged (fully covered), 2nd dentist they charged 120 (112 was covered), 3rd dentist was paid just about in full as well (even though it was not even a month after the second dentist) for the initial appt/exam... then two fillings (one big one in between two, actually) insurance paid 244.80, then there were the extractions (which took approx 2 minutes including the lidocaine) that insurance paid 193.60 for.
That's all before he was 2.5.
So yeah, I'd get a 4 year old under the plan, unless you really want to roll the dice that she won't need any work. When i compare what we pay insurance to what the cash charges would be from our dentists, it's about a wash. But as soon as someone needs work done, although dental insurance isn't all that *good*, it's generally still better than paying totally OOP.
Start finding a GOOD, sane, intelligent dentist for her (get referrals! ask people WHY they like the dentist! what works for someone else might not work for you), see what they charge for cash visits, compare to insurance...see what seems better.
If you lived in western WA I'd have two referrals for you, but ya don't so I can't help.
