We supported my MIL and SIL financially and they lived with us for 16 years and we never claimed them as dependents. Can I still do that?

[tkcroval]

My MIL and SIL lived with us and we financially supported them for 16 years.  We never claimed them as dependents.  Is this something we can go back and do?  Never knew we could claim them at the time.

[Vanessa A]

You can Amend Your Return for the past three years.  You cannot claim a refund further back than three years.

To claim someone as a Qualifying Relative, they must be:

• Your child ( including step children, adoptive children and foster children) or a descendent of them
• Your sibling (including half siblings) or a child of your sibling or a sibling-in-law
• Your parent or grandparents, including step parents and in laws
• Any other person that lived with you for the entire tax year
• Not a qualifying child of another taxpayer
• Someone that you provided over half of their support for during the tax year
• Has less than $5,050 in income (not counting social security)

[xmasbaby0]

You cannot go back for 16  years.    You can amend tax returns for up to three years back.   You have not mentioned whether your MIL or SIL had any income during those years.   For each of those years, there were certain amounts of income that had to be considered when determining if they could be claimed as dependents.  Did they have income --not counting any Social Security?   You only say they lived with you----did they work or receive any taxable income?

They might be "qualifying relative" dependents if they meet the criteria, and you could get the $500 credit for other dependents for claiming them--which is a non-refundable credit that lowers your tax due.

• They didn't provide more than half of their own support for the year.

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $5050 in 2024.   (Not counting Social Security)
• You provided more than half of their financial support.

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.

Related Information:

• What does "financially support another person" mean?

INCOME LIMITS FOR QUALIFIED RELATIVE

Each year the amount changes.  They have income less than

2024 $5,050

2023 $4,700

2022 $4,400

2021 $4,300

2020 $4,300

2019  $4,200

Wait until your original return has been fully processed before you amend, and make sure you have saved a pdf of the original return before you amend. (If you do not save it as a pdf, the amended return will overwrite the original, and the original will be lost forever)

See this TurboTax support FAQ for amending a tax return -

CURRENT YEAR

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-federal-tax-return-curr...

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a... 

Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.  

You can watch for information here:

https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1