Turbotax is following the law because box 16 is checked which requires completion of the k-3. unless you are a foreign unitholder or are getting foreign tax credits on line 21uncheck box 16 and enter no K-3 info. there probably is something in the transmittal letter that says the partnership's only income is US-sourced so US citizens except in the case of getting the FTC do not file K-3.
