FAFSA with 50/50 custody but uneven expenses - who should file when child support isn't collected?

From what I understand with the new FAFSA, it's based on who provides more financial support, not just income. Since you're covering most of his expenses, you should probably be the one filing.

UGH the FAFSA is the WORST for divorced parents!!! I went through this last year and it was a nightmare. The school financial aid office kept sending us back and forth between parents. Eventually they told us whoever the kid lived with MORE DAYS of the year should file. Since your son is with you 5 days/week and with dad only 2 days + some weekends, you should file. BUT keep all your receipts for everything you pay for him in case they question it.

The 2025-2026 FAFSA has specific guidelines for this situation. For parents with shared custody, the determining factor is which parent provided more financial support during the previous 12 months - not income level and not necessarily who claims the student on taxes. Since you're providing housing for more days of the year plus paying for health insurance, phone, and other major expenses, you would likely be considered the parent providing more financial support, even if your ex has higher income. The fact that you're not collecting child support doesn't change your status as the parent providing more support if you're covering most daily expenses. The 529 contributions are important for college, but don't count for determining FAFSA filing responsibility. If you complete the FAFSA (with your lower income), your son will likely receive a better financial aid package than if your higher-income ex-husband completes it.

I had this EXACT situation last year! After getting the runaround for weeks, I finally reached a FSA agent who explained it clearly. Since I provided housing for my daughter most of the year and paid for her health insurance, I was considered the supporting parent even though my ex made more money and contributed to a college fund. Trying to reach Federal Student Aid by phone was a nightmare though - I kept getting disconnected or waiting for hours. I finally used Claimyr.com which connected me to an agent in about 10 minutes. They have this service where they wait on hold for you and call when an agent is available. Saved me hours of frustration! You can see how it works in their video demo: https://youtu.be/TbC8dZQWYNQ Once I got through, the FSA agent confirmed that in 50/50 custody, the parent who provides more day-to-day financial support should complete the FAFSA, regardless of who claims the child on taxes or who has higher income.

something to consider - whoever fills it out, ur sons SAI (student aid index, what they used to call EFC) will be different. my sister and her ex did calculations both ways to see which would give their kid more aid money. since ur ex makes more, ur son might qualify for more grants if u file instead of him. just sayin

im confused why ur ex isnt just paying the child support he owes u?? that money could help u pay for college stuff now instead of being in some account u might not control. just saying...

HEADS UP on something nobody else mentioned - if you're the one filing the FAFSA, make SURE you list the 529 plan your ex contributes to!!! Even if it's in your ex's name, if your son is the beneficiary, it counts as a parent asset on the FAFSA if the parent filing is the owner. If your ex owns the 529 but you're filing the FAFSA, it doesn't get reported! THIS IS HUGE for aid calculations!! My neighbor got audited because her ex had a massive 529 for their kid but since mom filed FAFSA and didn't own the 529, she didn't report it, and got way more aid than they should've. When the school found out about the 529, they reduced the aid package and made them pay back some grants!!!

This won't help with your specific question but I'm just curious - has your son applied to schools yet? If he's looking at private universities they might require the CSS Profile too which asks for WAY more financial info than FAFSA, including from both parents sometimes even if divorced. My daughter had to get financial info from her dad who she barely speaks to because of this 😑

I went through something similar with my daughter two years ago! Based on everything you've described, you should definitely be the one filing the FAFSA. Since you're providing housing for 5 days/week plus covering health insurance, phone, clothes, and school expenses, you're clearly the parent providing more financial support - even though your ex has higher income. The key thing to remember is that the FAFSA rules look at WHO provides more support, not who COULD provide more support based on income. Keep records of all the expenses you pay for (insurance statements, receipts for clothes/school supplies, etc.) just in case you need to document it later. Also, filing with your lower income will likely result in a much better aid package for your son compared to if your ex filed. The difference could be thousands of dollars in grants vs loans. And don't worry about the tax dependency situation - that's completely separate from the FAFSA filing parent determination. One last tip: if any schools require the CSS Profile, that's where things get more complicated and they might want both parents' info regardless of who files the FAFSA.

Based on everything you've shared, you should absolutely be the one filing the FAFSA. The 2025-26 FAFSA determines the filing parent by who provides MORE financial support during the 12 months prior to filing - not who has higher income or who claims the tax dependency. Since you're providing housing 5 days/week, paying for health insurance, phone, clothes, and school expenses, you're clearly the supporting parent even though your ex has higher income. The fact that he contributes to a 529 instead of paying child support directly doesn't change this - day-to-day living expenses are what matter for the FAFSA determination. Filing with your lower income will likely result in a significantly lower SAI (Student Aid Index), which means your son could qualify for much more need-based aid including federal grants. This could literally save you thousands in college costs compared to if your higher-income ex filed. Just keep documentation of the major expenses you cover (insurance statements, receipts for school fees, medical expenses, etc.) in case you're ever asked to verify. And don't stress about the tax dependency - that's completely separate from FAFSA filing requirements. Good luck with the college process!

Just wanted to add one more thing that might be helpful - when you do file the FAFSA as the supporting parent, make sure you're consistent about this designation across all college applications and financial aid forms. Some schools might have their own supplemental aid forms that ask similar questions about custody arrangements. Also, since you mentioned your son is looking at both state and private schools, keep in mind that some state schools have additional state grant programs that might have different criteria than federal aid. It's worth checking if your state has any specific programs for divorced families or single parents. The good news is that you're getting this figured out now while he's still a senior - some parents don't realize the importance of the supporting parent determination until they're already deep in the financial aid process and it's harder to make changes.