The Retirement Savings Contributions Credit is a nonrefundable credit. This means that it and other nonrefundable credits cannot be used to reduce your income below zero. if it is appearing on Form 1040 line 51 you *are* getting benefit from the credit. However, because this credit is applied before certain other nonrefundable credits, it's possible that this credit is reducing the effect of some other credit on Form 1040 lines 52 through 54 to keep the amount on line 56 from going below zero. Some of the credits on lines 52 through 54 are subject to carryforward of the unused portion to next year (and beyond, if necessary).
