Indiana Code Title 32. Property § 32-17-11-17

Sec. 17. (a) Unless there is clear and convincing evidence of a different intent, during the lifetime of all parties, a joint account belongs to the parties in proportion to the net contributions by each party to the sums on deposit.

(b) Unless:

a trust account belongs beneficially to the trustee during the trustee's lifetime.  If at least two (2) parties are named as trustee on the account, subsection (a) governs the beneficial rights of the trustees during their lifetimes.  If there is an irrevocable trust, the account belongs beneficially to the beneficiary.