Determine Federal AGI

• 1). Collect W-2s from all jobs, regardless of the states from which they were issued.
  
  
• 2). Fill in the appropriate information in the header of your 1040 form: name, address, filing status, dependents, etc.
  
  
• 3). Add up all your income shown in Box 1 of each W-2 and put the total on line 7 of Form 1040.
  
  
• 4). Complete lines 8a through 21 for all relevant income and calculate total income on line 22. Deduct allowable adjustments to income on lines 23-35 and calculate your total adjusted gross income on line 37. This is your federal AGI and includes income earned in all states, minus all federally allowable adjustments to income.
  
  

Calculating State AGI

• 1). Consult the tax code for each state you lived in and earned income during the year to determine which state you are a resident of. If you lived in only one state but your employer sent you to different locations during the year, you will remain a resident of the state where your permanent residence is, but may have to file non-resident returns in the other states if state tax was withheld by a non-resident state.
  
  You will need to file a resident tax return in your state of legal residence on the last day of the tax year. You may be required to file a non-resident return for the other states. Each state provides detailed information on its website.
  
  
• 2). Complete the state tax return, using your federal AGI as a base, and adjusting income as necessary to account for income earned out of the state. Some states do not tax income earned in other states, while other states tax only income earned in other states and not income earned in the state. Each state has different laws.
  
  
• 3). File non-resident returns to reclaim withheld state taxes in any state for which you do not file a state tax return. For example, if you worked in California and state tax was withheld from your paycheck but you are a resident of Texas, you are entitled to receive a refund for the tax paid to California. You will find information on how to file a return for this refund on the state's tax board website.