My ex husband died last year, he still lived with me and I took care of him financially, he did not make but 600$ last year, can I claim him on my taxes

If he lived with you for the whole year in 2024 (up until he passed away) then you may be able to claim him as a "qualified relative" dependent for the $500 credit for other dependents, since you say he had less than $5050 of income.  

IRS interview to help determine who can be claimed:

https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent

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.