If you are one of many who have not claomed your 2016 tax refund, after July 15th it will become property of the U.S Treasury Department,
The 3 year window to file for 2016 closes after July 15. As of now, 1.4 million people are owed more than $1.5 billion from that tax year. There is no penalty for filing late as long as a refund in involved.