I finished my tax returns yesterday. I just found out that I can deduct my rent since I work from home. I was not given this option. Can this be changed?

For your federal return if you received a W2, you are an employee and cannot deduct any home office expenses. 

If you are an independent contractor, and received a 1099 instead of a W2, and if you did not yet submit your return, you would need to upgrade to TurboTax Self-Employed and walk through the income and expense section to report your home office expenses. If you already submitted your return and entered your 1099 but not the expenses, you will need to  Amend Your Return .  The amended forms are not yet available, so you will need to check late February to mid March for the amended forms availability.