message to open IRA and save $500 when MAGI is over limit is this an error?

Filing jointly we are getting a message from Turbo Tax for me to open an IRA and save $500.  I have a 401K plan from my employer and my MAGI is over the limit.  So is this an error?  My wife does not have an employer sponsored plan so she opened  deductible IRA and got the full tax deduction. When i tell turbotax i opened IRA I get 500 tax savings but my IRA is not deductible. This makes no sense. Why nondeductible IRA gives tax savings?