You will have to file 2028-29 FAFSA using 2026 taxes and IRS DRT (data retrieval tool), with no option to make edits. You will use assets as of the day you file FAFSA (and CSS as applicable.) Both forms typically open Oct 1 for the next year. There is no field to explain changes in the FAFSA, but there is at least one question in the CSS to explain a change in circumstances.
If there were material changes in 2026/27/28, you will have to speak with each school’s financial aid department, asking for professional judgment. Follow each school’s process, typically detailed on the FA website. Some have a form to fill out.
There are a select few schools where you can get a financial aid pre-read before applying. This list is a good start, but verify details on each school’s website. If you do one/a few of these, it might be indicative of how discussions go with other schools. Financial Pre-reads, including merit + merit ED
NPCs at many schools should be accurate for the baseline need-based FA estimates, but as you probably know, many NPCs don’t estimate merit. Note that NPCs may not be accurate if parents are divorced, own a business and/or real estate beyond a primary home…are any of those the case for you?
If merit is important, you might prioritize schools that use merit award grids based on stats (so an actual number or relatively tight range is knowable before applying.) Also use the common data sets (CDS) section H to see average merit awards, which may help you add/subtract schools from the list.