Sorry to be a pain, but I am sure you can understand how confusing this issue is. So I thought I would give more details:
In this case, there is 1 child. Parents divorced in 2010. They have agreed to split custody with the child 50/50. They have been alternating taking the child as a dependent each year; on the year the other does not take the child, they were filing as Single. The Spouse has since remarried so I assume he is now filing as either MFJ or MFS. I did TP return for 2018; she took the dependent. I am now doing her 2019 return and trying to determine if she can file as HOH. I believe she is the Custodial Parent because of her salary. So my take is that she can take HOH and send an 8332 for to the Spouse, and send one separately to the IRS. My source for this is the Pub 504, pages 22 - 24, Children of Divorced or Separated Parents.
