I have multiple questions: My wife's parents lived in our home in FL in 2023 and 2024. They only have/had social security payments for which they never filed returns in either year. They both lived in our home for all of 2023 and we supported them 100% excluding the social security payments. I believe we can take both of them on our taxes for 2023 but 2024 became a little tricky. My father-in-law passed away in January 2024. If I am correct about our 2023 return, am I also correct in thinking that we can take both of them for the 2024 tax year?
It depends. To claim your parents you must provide more than half of their support. If any of their money went into savings accounts and remained there during the tax year then that money doesn't count towards their support.
Review the information for qualifying relatives. If they qualify, including your father-in-law who passed away, you can claim them. He will be considered to have lived the entire year for dependent. I have included a dependent worksheet to help with support.