schedule c income less the se tax on schedule 1 line 14 less the 401(k) contribution schedule 1 line 15 less your se health insurance schedule 1 line 16 should be greater than or equal to zero. it should not be negative. you have entered something incorrectly. did you put your se health in the proper box on schedule C?
there should be a worksheet for health and long-term care as part of schedule c. on line B of that form you must input manually the 401k contribution which can not exceed the amount that's precomputed and listed a little to the left. thus if you make the max 401k contribution the deduction for se health on schedule 1 line 16 drops to zero so net schedule C less se tax less 401k is zero.
