Earned Income & Additional Medicare Tax

[Nate X]

For plan years after 2012, does the new additional medicare tax reduce a self-employed person's earned income for retirement plan purposes?

[Belgarath]

Do you mean the 0.9% additional tax? If so, then the answer is no. This is paid at the "employee" level, and doesn't affect the 164(f) deduction. So it doesn't enter into the earned income reduction calculation.