Everything points to the fact that TurboTax can simply export its own forms (for example .tax2016) to a PDF document, which is what tax2016 to pdf conversion actually represents. This can be done either with a dedicated export PDF function, or via a virtual PDF printer accessible through the File ► Print function. This procedure is typically done for printing or publishing purposes.
It is likely that without TurboTax it will be close to impossible, to produce a PDF document from a .tax2016 file.Open TAX2016 file Open PDF file
A tax preparation software developed by Intuit
A popular tax preparation software