There's not an
income limit, per se, but something would appear to be disqualifying the credit
based on information you've input.
It could be that
you've received Dependent Care Benefits on your Form W-2 that generated in Part
III of Form 2441, that caused your expenses to zero out, or that you or your spouse don't have earned income.
Please see
Form 2441, the Instructions for Form 2441,
and the TurboTax FAQ "What
is the Child and Dependent Care Credit?" below for more
possibilities as to what's disqualifying the credit.
https://ttlc.intuit.com/replies/3301418