From a release by the White House:

President Joe Biden's American Rescue Plan includes investments to support low and middle-income families who have long faced increasing financial strain - more so now because of the pandemic. Many Families need financial relief and support to be able to return to work or continue working so they can provide economic security for their families.
The American Rescue Plan delivers major tax relief for working families with children through a historic expansion of the Child Tax Credit. In 2021, for most families, the Child Tax Credit is increased to $3000 for each child between ages 6 and 17 and to $3,600 for children under 6. ​

1 Child (under 6)
2 Children (under 6)
Total:
$3,600
​$7,200
Monthly:
$300
​$600

1 Child (age 6-17)
2 Children (ages 6-17)
​
Total:
​$3,000
​$6,000
Monthly:
​$250
​$500

How does it work?

Tax relief is typically available only when you file your taxes, however this Plan will provide monthly payments for the first time ever. To help with the costs of raising children, families will begin to receive monthly payments of $250 per child between ages 6 and 17 or $300 per child under 6, starting July 15, 2021. 

An estimated 39 million households will begin receiving payments without any further action required. Families who have not yet filed taxes in 2019 or 2020 and who did not sign-up for Economic Impact Payments like the $1,400 rescue payments included in the American Rescue Plan can still sign-up to receive the Child Tax Credit.

Experts project that the expanded Child Tax Credit could potentially help lift one-half of all children out of poverty if all eligible families sign-up to receive the credit.

Child and Dependent Care Tax Credit

The American Rescue Plan's historic expansion of the Child and Dependent Care Tax Credit (CDCTC) will make child care more affordable for millions of working families in 2021. Specifically:
  • A median income family with two (2) kids under age 13 will receive up to $8,000 towards their child care expenses when they file taxes for 2021, compared with a maximum of $1,200 the previous year.
  • All families with incomes up to $125,000 will save up to one-half the cost of their eligible child care expenses, getting up to $4,000 for one child and $8,000 for two or more. 
  • The CDCTC will be fully refundable by allowing low-income working families to receive the full value of the credit towards their eligible child care expenses regardless of how much they owe on their 2021 taxes.                                                      
The American Families Plan and American Jobs Plan will reimagine and rebuild a new, stronger economy that leaves no one behind. They will extend the historic increase in the Child Tax Credit included in the American Rescue Plan; Guarantee low and middle-income families will spend no more than 7% of their income on high quality child care for young children; Make permanent the American Rescue Plan's expansion of the Child and Dependent Care Tax Credit; And build the supply of Child Care.
For more information on the Child Tax Credit, visit IRS.gov.