@Howard424
TurboTax should not even be asking whether your spouse can be claimed as a dependent on an MFS return. The IRS instructions say that that box (on Form 1040 line 12a) should only be checked if you are filing jointly. That's why Smart Check is flagging it as an error. Your spouse being a dependent has no effect on an MFS return.
What I think you should do is go back to the spouse information and answer No to the question "Can anybody else claim [Spouse] as their dependent for 2025? It won't make any difference in your tax return, and everything else should proceed normally.
