Tax Implications for First Party Special Needs (Grantor) Trust

A self-settled, first party special needs trust was recently established for my child with their assets. My spouse and I serve as trustees.

For any non-distributed capital gains or income/dividends earned by invested assets in the trust, how are taxes handled? My understanding is this is considered a grantor trust according to the Internal Revenue Code Title 26 §§671-4 (https://www.irs.gov/pub/irs-tege/eotopicf01.pdf; https://www.law.cornell.edu/uscode/text ... /subpart-E).

So would any income or gains from the trust be filed on a Form 1040 for my child? How do taxes on capital gains work for grantor trusts?

Any expert insight would be greatly appreciated as we plan ahead.