I live with my boyfriend at his dads house. My mom is the one who supports me 100%. With that being said, does my boyfriend have the right to claim me as his dependent?

[xmasbaby0]

Here are the rules for who can claim a dependent.  Do you qualify as your Mom's qualifying child or BF's qualifying relative?

WHO CAN I CLAIM AS A DEPENDENT?

You can claim a child, relative, friend, fiance (etc.) as a dependent on your 2019 taxes as long as they meet the following requirements:

Qualifying child

• They are related to you.

• They cannot be claimed as a dependent by someone else.

• They are a U.S. citizen, resident alien, national, or a Canadian or   Mexican resident.

• They are not filing a joint return with their spouse.

• They are under the age of 19 (or 24 for full-time students).

• No age limit for permanently and totally disabled children

  •      They live with you for more than half the year (exceptions apply).

Qualifying relative

• They don't have to be related to you (despite the name).

• They cannot be claimed as a dependent by someone else.

• They are a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.

• They are not filing a joint return with their spouse.

• They lived with you the entire year.

• They made less than $4200  (not counting Social Security)

• You provided more than half of their financial support. More info

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them.

Related Information:

• Does a dependent have to live with me?

• What does "financially support another person" mean?

• Can I claim a newborn baby?

[NCperson]

@chelder93 - from what little information your provided, sounds like your boyfriend's PARENTS may be the ones who can claim you,

1) you do not live with your mother so that disqualifies you to be her dependent.

2) does your boyfriend pay your fair share of rent /mortgage, utilities, food, insurance, etc on your behalf? sounds like "no" since you state your Mom is paying for everything (does 'everything' include the rent to boyfriend's parents?) .. But if his parents are not charging you for rent, utilities, food, etc. 

how much is your income? if over $4200, no one can claim you! 

please read closely what @xmasbaby0 provided as the rules for a "qualifying relative"