When there is a decision that needs to be made between you and another person. It would be good if it has connotations of a presumed expertise. For example, if you and another person were looking for an answer to a complex problem, either party could make the decision but you believe their decision would be best. Something like "I defer to you for this decision", or "I concede the decision to you". Neither of the words are what I believe I'm looking for.
You can use "entrust"
"I entrust this decision to you."
Both meaning you trust the other person to make the decision* (see note below), and also are placing the responsibility for making the decision in the hands of that person.
- To give over (something) to another for care, protection, or performance
American Heritage Dictionary
*Actually I may have been wrong about the first point. The proposition that you trust the other person is implied, not necessary, when entrusting a task to another.
This is clarified by this usage note in Collins English Dictionary:
Usage: It is usually considered incorrect to talk about entrusting someone to do something: the army cannot be trusted (not entrusted) to carry out orders
Collins English Dictionary