EFC doubled for 17/18 school year

Our estimated family contribution doubled - from 12K to 25K in one school year. Absolutely nothing has changed. In fact, even the tax return year used (2015) is the same! Has this happened to anyone else, or does anyone know why?

Did any kids graduate from college?

Student and parent assets are exactly the same from one year to the next? Number of family members is the same? Number of college students is the same? Age of the oldest parent is the same? (Yes, this is used in the FAFSA EFC calculation, but it shouldn’t make a $13k difference.)

My guess is that an error was made in completing the form, either this year or last year. Compare the numbers line by line.

We had another kid in college and I did fill out the FAFSA for him, but he ended up not attending. That was probably it! Thanks so much for your help! I have spent hours searching online before coming across this forum. Wish I had gone here first!