CNN ran a similar story a couple of years later (last year) with same expert Jacobson, with updated numbers:

Why billions of dollars in lottery prizes go unclaimed

There are literally billions of dollars in unclaimed lottery prizes each year, according to research from lottery expert Brett Jacobson. He collects data from every state lottery commission for a lottery app he runs, and his data shows there were $2.89 billion in unclaimed lottery prizes in the 12 months ending June 2017.