With the health insurance change until you're 26, does my dad have to wait until open enrollment or can he?

I'm 24, my dad had to take me off his insurance when i was 23 because the law. I now understand the law changed until 26 effective 9/23/2010. Can my dad call and add me on currently since the law was changed or will he still have to wait until open enrollment? I know normally you have to wait but since this was a law being changed I thought it might work differently.
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Most carriers are allowing enrollment for effected children outside of open enrollment but they aren't required to. He needs to call.
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