My mother was caring for my special needs sister until last year when she passed away in 2024. I am now my sister’s caregiver. Can I claim head of household?

Yes, you may file as Head of Household.

You can claim a child, relative, friend, fiancé(e), and so on as a dependent on your 2024 taxes as long as they meet the following requirements:

Qualifying child:

They're related to you.
They aren't claimed as a dependent by someone else.
They're a US citizen, resident alien, national, or a Canadian or Mexican resident.
They aren’t filing a joint return with their spouse.
They're under the age of 19 (or 24 for full-time students).
There's no age limit for permanently and totally disabled children.
They lived with you for more than half the year (exceptions apply; e.g., away at school; in a care facility where they lived during the year).
They didn't provide more than half of their own support for the year.
 

When you add someone as a dependent, the program will 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.

For more information, see this helpful TurboTax article: Guide to Filing Taxes as Head of Household

I'm very sorry for the loss of your Mom.