"there is no provision for this and in fact, the program does not recognize it. "
In recent years, TurboTax has moved the question of the type of pension on the state level from the state interview to the 1099-R interview.
That is, go back to the 1099-R interview (Search for 1099-R and click on the jump-to result) and edit your 1099-R entry.
Be sure to go all the way through the 1099-R interview. Eventually, you will be asked what state this belongs to, and when you answer "Missouri", it will ask you what the source of the pension is.
This information is carried to the Missouri return to be handled appropriately.
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