This question is not A&M specific but was instigated by an email from A&M saying it’s time to fill out the FAFSA. I had pretty much decided not to fill the FAFSA since we will not qualify for need based financial aid. Just wanted to get a second opinion that there are others doing the same.
FAFSA is required for some scholarships that are merit based. If you opt out, those will not be in play for your student. We did fill out FAFSA ( do NOT qualify for need) so that our kids would be eligible for all scholarship opportunities. Does it count against you? Yes, but can be overcome on the matrix with other stats and you would otherwise not even be considered.
FWIW, our S & D both got awarded scholarships with FAFSA filing requirements. However, we were also told that her Freshman year our FAFSA was way too high to even be considered for certain merit scholarships that required FAFSA (ours was near maximum with one in school), so only some of those with FAFSA requirements are in play if you’re at the top end of the scale. Also, we fell over laughing when we got our FAFSA - well I mean after the butler & personal assistant delivered it to us at our summer house on the yacht. 
@axonta - If you don’t expect to qualify for financial aid and you or your parents don’t intend to get federal student or parent loans, then don’t bother. But the FAFSA is a prerequisite for the college to calculate your Expected Family Contribution. It sounds like the EFC in your case will be the entire estimated Cost of Attendance. The EFC then allows a student or parent to qualify for student or parent loans.
Put another way, no FAFSA, no federal student or parent loans.
We will not qualify for any need based aid but contemplating filling out FAFSA. One school told me it is recommended to do in case aid is needed in the future (siblings, change in job situation). After freshman year, it is more difficult to receive. An appeal would need to be made. I think each school is different.
An admissions counselor I spoke with recently recommended that everyone submit the FAFSA each year regardless of financial need. It can be a safety net for your family if you experience a catastrophic event which drastically changes your family’s financial situation. Without a FAFSA on file, emergency aid would not be available to you if needed.