Turbo Tax would not allow me to efile until I went to the forms view and entered zeros in column A (for those months that were zero) and blanks in column C (for those same months.) Glad there's a solution that works but it's darned frustrating to spend the time to research and experiment with this. This is not an uncommon situation - - there could be a number of reasons why a taxpayer has ACA for only part of a year. TurboTax ought to fix this!!
