You are seeing this because the amount of Medicare taxes withheld in box 6 is not exactly 1.45% of the Medicare wages in box 5, due to rounding.
DoninGA found that if you remove any cents for the Medicare wages (Box 5), this will clear the need for Form 8959.
Double check your entries for your W2s. You could have a Box 6 withholding error or misplaced decimal point in Box 5 (e.g., entering $50,000.00 as $500,000) will trigger the form.
If the amount in Box 6 (Medicare tax withheld) is more than 1.45% of the amount in Box 5 (Medicare wages), TurboTax must generate Form 8959 to claim a refund of that overpayment. Even a discrepancy of $1 due to employer rounding can trigger this.
If your W2 entries are correct, delete the form: