Some terminology that you may need to understand:
MAGI - Modified Adjusted Gross Income is the amount you see on Line 37 of your Form 1040. This is all of your income less any adjustments such as Self-Employment Tax or IRA contributions.
Unearned Income - Unearned Income is generally income you have earned from investments. It includes, but is not limited to, Interest Income; Dividend Income; Income from S-Corporations; Rental Income for non-Realtors; Royalties; Trust Income and other income that appears on Line 17 of the Form 1040. Beginning January 1, 2013 certain unearned income exceeding the "High Earner" threshhold is subject to an additional tax of 3.8% (See Tax Updates-NIIT).
K-1 - You will receive a Form K-1 if you are a Shareholder in an S-Corporation; have Trust Income; belong to a Partnership or LLC or LLP. The K-1 will show what your earnings or losses are from that entity and must be reported on your Individual Income Tax Return.
ACA - The Patient Protection and Affordable Care Act (PPACA) is often referred to as the ACA or "Obamacare" and provides health insurance guarantees for American Citizens.