Apple CEO Tim Cook is expected to testify before a Senate subcommittee Tuesday to refute charges the company paid no taxes on tens of billions of dollars in overseas income. The Senate’s Permanent Subcommittee on Investigations is expected to release findings Tuesday claiming Apple didn’t pay taxes on at least $74 billion in overseas income. In response, Apple has released a statement explaining that the U.S. tax system “has not kept pace with the advent of the digital age and rapidly changing global economy” and that the company has paid “an extraordinary amount in U.S. taxes.” The Senate contends that Apple set up subsidiaries in other countries for which it paid no taxes to any government. However, Apple says the units were not designed to avoid taxes, but because the company sells the majority — 61% — of its products outside the U.S.