Other financial discussions

Not sure what you mean by "helping your mom" by being claimed as her dependent.  Either you can be claimed or you can't.  She does not need your permission to claim you if you meet the criteria to be claimed as a dependent.

Were you a qualifying relative?    You cannot be a qualifying child due to your age, but you could be a qualifying relative if you had less than $4200 of income in 2019.  If your income was more than $4200, then your mother needs to amend her return, and you file your own return that says you cannot be claimed, and the IRS will have to sort it out.  Since your SSN is already in the system for the year, you cannot e-file.  Your return has to be mailed.

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?