Why am I getting less than $13,200 total (incl. $6400 in Advance) for my 2021 Child Tax Credit, for 2 kids under 6 and 2 kids over?

[fanfare]

You must have made less than certain income limits.

See Schedule 8812 Part I

[thewisemans18]

I'll try to remember to run through TurboTax's filled-in Schedule 8812 when I finish putting my taxes together.

[xmasbaby0]

You are not going to see $13,200 on your Form 1040.   You are only going to see the difference between the amount you got in advance and the amount you can still receive.

Federal>Deductions and Credits>You and Your Family>Child Tax Credit

The IRS is sending out letter 6419 to you.  It will show the amount of advance child tax credit that you received during 2021.  Enter the information from that letter carefully.   

The remaining amount of CTC that you can receive will show up on line 28 of your 2021 Form 1040.   Then it will calculate down to the refund you see on line 35a or the tax due on line 37.

PREVIEW 1040

https://ttlc.intuit.com/questions/1901539-how-do-i-preview-my-turbotax-online-return-before-filing

Click on Tax Tools on the left side of the screen. Click on Tools. Click on View Tax Summary. Click on Preview my 1040 on the left side of the screen.

NOTE:   The CTC is indeed a “credit” that can be applied toward any tax liability that you would otherwise have to pay as “tax due”  to the IRS.