why is it saying I have Additional Medicare Tax (Form 8959)? I did not add any forms related to this. Only a W2 and standard deductions.

[VolvoGirl]

If you have high wages or earned income there is an extra Medicare tax on Schedule 2 line 11 which goes to 1040 line 23. That is offset with an extra amount of withholding on 1040 line 25c.  Check your W2 entries, maybe you left out a decimal point or added some digits in the amount.

What is Form 8959
https://ttlc.intuit.com/turbotax-support/en-us/help-article/medical-tax-credits-deductions/form-8959...