What underporting of income to IRS results in prosecution?

Underreporting income to the IRS can lead to prosecution if the discrepancy is deemed willful or fraudulent. This includes intentionally omitting significant amounts of income, falsifying documents, or engaging in schemes to evade taxes. The IRS typically pursues criminal charges when the underreporting involves substantial amounts, persistent patterns, or other indicators of tax evasion. Penalties can include fines and imprisonment, depending on the severity of the offense.