Earned income includes all the taxable income and wages you get from working.
There are two ways to get earned income:
You work for someone who pays you or You work in a business you own or run
Taxable earned income includes:
Nontaxable Combat Pay election. You can elect to have your nontaxable combat pay included in earned income for EITC. The amount of your nontaxable combat pay should be shown on your Form W-2, in box 12, with code Q. Electing to include nontaxable combat pay in earned income may increase or decrease your EITC. See Publication 3. Armed Forces Tax Guide, for more information.