Hi and welcome to Just Answer!That is what the IRS provides -
Q.7 I have a carryover from earlier years. Is the carryover amount refundable in 2010?
A. Yes. If you carried forward an adoption credit from 2005 or later (because the credit was more than the tax you owed), you can claim the carried-forward amount as a refundable credit in 2010. You can find the amount of any unused carry forward amount on line 23 of the worksheet on page 5 of the 2009 Form 8839, Qualified Adoption Expenses.See for reference - http://www.irs.gov/individuals/article/0,,id=231663,00.html
Thus if your credit was not fully used in 2009 - you may carry forward unused amount to 2010 and used it.If however - the credit was fully used - there is nothing to carry forward.You may not decide if you want to use a credit in 2009 or carry forward to the following year - the worksheet mentioned above will provide you with the amount to carry forward.Let me know if you need any help.