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Is it sufficient to just report the interest i've earned with it by entering my 1099-INT info in my tax return?"
Yes. The interest earned after the distribution is reported on your personal income tax return. If you did not receive a K-1 from the trustee, then you either received a distribution of corpus (principal) of the trust or the distribution was otherwise not taxable to you (e.g., the trust paid any tax due on the income).
You should check with the trustee to make sure the fact that you did not receive a K-1 was not an oversight.
