M name was put in trust on a certificate of deposit. The owner has died and the cd has matured and I wish cash it. Do I pay taxes on it as the beneficiary?

Don't take this as legal advice, but the likely answer is that you would owe taxes on the interest that has accrued since the death of the owner. There are issues that could affect this though, such as your relationship to the owner, the size and disposition of the owner's estate, etc.