Form 1040 not recording SSA-1099 info correctly. Any explanation?

[null265]

Form 1040 is not recording SSA-1099 info right.  SSA-1099 boxes 3 & 5 say $15,840. Medicare Part B says $1,608. Paid is $14,232.  All correct.  But 1040 (5a) records $15,840, and (5b) taxable amount is $13,464.  That a $768 difference (in may favor).  Any explanation for the difference? What can I do if TurboTax miscalculates?

[Rainman12]

Most likely correct as displayed. Taxable amount varies depending on your other income.