Why will Turbotax not let me put my excluded gain on my main home sale on line 15 of Form 6252?

[IsabellaG · Accepted solution]

Did you enter your installment sale information as part of entering the sale of your principal residence, rather than in the Installment Sale section? Because if you enter the sale in the Sale of Residence section, the excluded gain will be transferred to line 15 of Form 6252 automatically. If you enter it in the installment sale section, it won't be treated as the sale of a principal residence.