Can I still claim for an eligible dependent for 2016 even though I've already filed? If so, how do I fix this?

[TurboTax-Peky · Accepted solution]

Form T1ADJ can be found here: https://www.canada.ca/en/revenue-agency/services/forms-publications/forms/t1-t1-adj.html  Both fillable and blank versions are available.

If you're a CRA My Account holder, you can do the adjustment online instead. Once you've logged in, choose the "change a return" option from the left side menu.