refundable tax credit

科普文章哈。从IRS抄来的，绝对正确。：）

Refundable Tax Credits

A refundable tax credit is a tax credit that can reduce your tax liability below zero (0). Because it is possible to receive a refund from this type of credit, they're referred to as refundable.

Refundable tax credits include:

• Earned Income Credit
• Adoption Credit(now refundable for adoptions finalized in 2010 or 2011, or for carryforwards)
• First-time Homebuyer Credit
• Excess Social Security Credit
• Additional Child Tax Credit
• Health Coverage Tax Credit
• American Opportunity Credit- partly refundable

再加一句，refundable tax credit 都是鼓励穷人的，收入过了5万基本上就拿不到了。拿不到也别丧气，说明你是有钱人。：）