@5983387 while I am not familiar with the screens for the on-line product, I suspect you must have selected not to use the "simplified " computation of the credit. When I use simplified computation, it does not ask for the "basis", "adjustment to basis" or "adjusted basis "-- it just uses the world income, amount of each foreign source income, distributes the deduction ( standard or itemized" between the incomes and then allocates the US tax on each of the foreign source income.
Note that form 1116 allocates and thereby computes the Foreign Tax Credit as the lesser of the US tax and the foreign tax paid on the same doubly taxed income. This allowable credit being Non-refundable gets further limited by final tax liability -- FTC can only reduce your otherwise tax liability -- the rest is available for carry-over ( backward 1 year or forward till quenched /10 years ).
If nothing else helps, I would use the adjusted basis as the original basis i.e. use an adjustment of zero or blank ( one user reported that Turbo did not like "0" and so perhaps the blank is a better choice.
IF you need more help on this, please provide details of the situation, including foreign source country/type, passive ( INT/DIV/ Rental income etc. ) -- the more details the more focused the solution/answer.
Is there more I can do for you ?
