You only have to provide income information if you want to apply for Medicaid or advanced premium tax credits (help paying). If you are sure that you will not qualify, then you can skip that whole process. You may still get tax credits at the end of the year.
Note: If you work with a non-profit navigator or other government facilitated helper, they will encourage you to apply “just in case”. Many of our clients use the exchange because they are self-employed, but know they obviously make more than maximum for help. Check your state exchange or healthcare.gov to be sure.