Not necessarily. Certain relatives may qualify as dependents even if they don't live with you:
Children (including legally adopted), stepchildren, foster children, or any of their descendants
Siblings, including half and step siblings
Parents and their direct ancestors (excluding foster parents)
Aunts and uncles, nieces and nephews
Fathers-in-law, mothers-in-law, sons-in-law, daughters-in-law, brothers-in-law, and sisters-in-law
Any of these relationships that were established by marriage and not ended by divorce or death.
To be claimed as a dependent, your relative must also:
Have been a U.S. citizen or resident, or a resident of Canada or Mexico for at least part of the year;
Received less than $4,150 gross income (except nontaxable Social Security benefits) in 2018;
Received more than 50% of their support from you (this is why incarcerated relatives almost never qualify);
Not be claimed as a dependent by another taxpayer;
Not file a joint return with another taxpayer.
In addition, children that were under 19 at the end of 2018 (24 if they attended school full time for at least part of five calendar months of the year) must have lived with you for more than half of the year to be claimed. There are special rules for children of divorced or separated parents and for persons receiving support from two or more individuals.
As you go through the My Info section in TurboTax, we'll ask a series of questions to determine if somebody qualifies as your dependent.