Taxpayer has made $18000 in nondeductible IRA contributions. He’s 72 but still working and $6000 was made for 2021 (but I’m not sure if it was made in 2022 or not. Sending an email). Anyways, if box 4 is zero, it uses up all of the basis in the IRA this year, since the RMD was over $18000. If I put $6000 in box 4, none of the RMD is non taxable. Shouldn’t the non taxable portion be a fraction of the amount?