The tax calculated on Form 8960 is the Net Investment Tax, which is basically Medicare tax on investment income when your AGI is above the threshold. If Form 8959 shows additional Medicare tax due, it means your employer did not withhold enough Medicare tax from you wages, and/or you had self-employment income.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
