Can a grandparent claim grandkids that live with their mom in that household if me the father wants to claim them and i provide half of their support via money medicaletc

[macuser_22]

If the child lived with both the parent and the grandparent for more than half the year, it makes no difference who pays for the child's support as long as the child did not pay for his/her own support. 

The child can be the qualifying child dependent of either the parent or grandparent - you can decide which claims the child.  In the case that you cannot decide then the parent prevails.

The absent father that did not live with the child cannot claim anything unless the mother releases the exemption (and child tax credit) to him with a signed 8332 form.  If she does so then she (the mother) or grand parent can still claim the child for EIC and the child care credit.

If there is a decree or court order that the father can claim the child's exemption then the mother can be compelled to issue a 8332 form to the father.   That would have to be enforced by the local court, the IRS only goes by physical custody unless there is a 8332 form with the absent parents tax return.

[Tmselph72]

This has been many years ago, but I was living with my father and my 3 children while I was working and going to school but my father insisted that he claim my children. I feel that he cheated me out of my earned income credit. Is there anything that I can do?

[Mike9241]

you used someone else's question which makes responding difficult because only the above title shows up in the e-mail we get and not the question you are asking which differs in detail.

many years ago would seem to indicate that this occurred prior to 2018 in which case it's too late to file amended returns.

however to answer your question. the children seem to be qualifying children of both you and their grandfather. the tax laws say in cases where multiple people can claim a person as a qualifying child it's the parent that gets to claim them. 

who supported the children is irrelevant 

you mention nothing about their mother because if she lived with you and her adjusted gross income was higher than yours, then it would e her that could properly claim the children if no joint return was filed. 

[Hal_Al]

Q.  I feel that he cheated me out of my earned income credit. Is there anything that I can do?

A. No. For two reasons. 

1. When the children live in a household with more than one relative, it's basically optional, which relative claims the child (if the non parent [grandparent in this case] has a higher income than the parent). Since, you didn't try to claim them yourself, at the time, you essentially consented to the grandparent claiming them.

2. "This has been many years ago".  There's a 3 year limit to filing amended returns. 

Since the grandparent had the higher income, it's almost certain that he got more tax benefit from claiming them than you did.  So, overall, the family came out better doing it that way. 

If there are circumsatnces where that might not be the case (e.g. grandparent didn't qualify for EIC), it might have been worthwhile to crunch the numbers to see who shoulda claimed the kids.  It  may have even be that you should have split the children (that is allowed).  If it's been more than 3 years ago, there's nothing you can do now.