"The House budget would make nearly every problem children face worse," said First Focus President Bruce Lesley in a statement.
"The Senate plan recognizes that we can't build a stronger tomorrow for children by denying them the things they need to succeed today."
The House and Senate plans are vastly different in the way they approach the federal budget.
Ryan's proposal would block-grant Medicaid, for example, forcing millions out of the program. The plan balances the budget in 10 years.
The Senate budget from Patty Murray (D-Wash.) would maintain the expansion of the program under President Obama's healthcare law. It would reduce deficits by $1.8 trillion over 10 years.
First Focus praised Murray's budget for explicitly stating that half of Medicaid beneficiaries are kids.
On food stamps, WIC, early-childhood investments and tax credits benefiting kids, the group praised the Senate plan.
"Children are not the cause of our fiscal imbalance," the report stated, "and cutting investments that help them grow is a poor decision."
Ryan argues that his budget cuts are necessary to stabilize the U.S. debt, an outcome that will benefit future generations.