Can a non custodial parent who pays child support and is allowed to claim one child on income tax be a head of household?

[owe2much2]

can someone explain Box 12 a,b,c, on the W-2?

[Critter-3]

NO ... the non custodial parent can only claim the dependent exemption and the Child Tax Credit if the custodial parent gives them permission by giving them a signed form 8332.   The HOH filing status, EIC & Day care credit remain with the custodial parent. 

And the box 12 entries each have a code ... look on the back of the W-2 form for the chart. 

https://twonline-21.taxwise.com/Help/WebHelp/Content/IRS%20Codes/English/Miscellaneous_Codes/W-2_Box...