The client has no idea. They never do. I know the correct, text book answer is, "Ask the client what the basis of the IRA was at year-end," but the answer is always the same. The client says, "What does that mean?"

Expecting the client to know this is ludicrous. If the bank says "X amount is taxable," then why not accept that?

Did I mention the box "taxable amount not determined" is NOT checked? If the bank didn't know whether there were any nontaxable contributions, they would just check that box, like they always do. Then sure, it's 100% taxable. The fact that they put a different amount in box 2a says they have specific information. 

Since the return is due today, "doing homework" is not an option.

Like I said, if the bank knows that X is the amount that is taxable, and the 2b box is not checked, why would ProSeries not accept that answer?