Me and my ex-wife have 4 children together ,in the divorce I would get the two boys and she would receive the girls ,I fell behind in child support in the early 2000 due to lack of work ,she has not let me claim any of the children for the last ten years , my question is can she let her significant other claim any of my children ,even thou I am behind in support ,and I have paid above more in most years ,but still behind .if she didn't what to claim the girls ,would the other biological parent be able to claim before her significant other ,and would I be able get those exemptions back in all those years or sue for them.
Mike

"she has not let me claim any of the children for the last ten years "

What makes you think she could have stopped you? If the boys lived with you more than half the year and you provided half their support then you are entitled to claim them.

As for her significant other, it depends on how they file, If they file jointly and the girls live with them then he can claim them.

I suggest you you check IRS.gov there is a booklet on who can claim children in a divorce.

P.S. its not a good idea to piggyback your question on another thread. This can lead to confusion. So I've moved your question to its own thread.

If it is specified in the divorce decree that you get two children and she gets two children, then the IRS MUST abide by that decree, because it is BOTH a court document AND a legal contract.

Claim your two sons. You can start by amending your 2009 tax return. Attach a copy of the divorce decree to the amendment and explain the facts. Once the refund arrives, then do the 2010 and 2011 amendment.

Just to add here, if someone else claimed them for 2009, it might take some times for the IRS to investigate and agree to amend your return. It also means they will call the other claimant in for an audit since their deduction will have been disallowed.