Can Inherited Roth IRA be merged with existing Roth IRA?
No, the inherited funds (beneficiary IRA) have to remain in
inherited (beneficiary) form. So the account/funds can only be
distributed out of the beneficary IRA as a distribution or transfer
to another alike roth beneficiary account at another firm.
However, the deceased account can be transferred into the
surviving spouse Roth IRA (or transfer to a beneficiary IRA
account). A non-spouse doesn't have this option- they can only
transfer to their beneficiary IRA account that they opened.