IRA investing as a senior

My husband is 75, I am 70.  He works full time.  Are we able to pay into or start an IRA to invest at our age.  We both are on social security and receive an RMD on two IRA's that we have.  One was set up when he was in a solo business under a Defined Benefit Plan and the other was a simple IRA.  We'd like to invest to reduce our taxes if possible for next year