Without looking at your return it is impossible to know why. These are the most common things that effect your refund or balance due: Change in Filing Status; Change in dependents claimed; No longer have a child, under age 17, to claim the Child Tax Credit The amount of federal and/or state withholding; Income based credits, such as the Earned Income credit; Tax bracket changes Here is a TurboTax Help Article that will give you more information..