This is what I found searching the web.
AmeriCorps Segal Award taxation
The Segal AmeriCorps Education Award is considered taxable income in the year it is used. This means that all payments made from the education award in the year they are used should be included as taxable income for that year. AmeriCorps does not withhold taxes from the award.
For more detailed information on the Segal AmeriCorps Education Award, including eligibility, use, and tax implications, you can refer to the official AmeriCorps website.
https://www.americorps.gov/members-volunteers/segal-americorps-education-award/find-out-more
since your award was under $600 you will not get a 1099-misc. and per the website the amount is taxable for state purposes
so it seems you did not include the amount as income on your returns which will require you to amend them.
