I:1-48 Statute of Limitations. In April 2022, Dan is audited by the IRS for the year 2020. During the course of the audit, the agent discovers that Dan’s deductions for business travel are unsubstantiated and a $600 deficiency assessment is proposed for the tax year 2020.

The agent also examined some prior year returns. The agent discovers that Dan failed to report $40,000 of gross business income on his 2018 return. His gross income in 2020 was $60,000. The agent also discovers that Dan failed to file a tax return in 2013.

Will the statute of limitations prevent the IRS from issuing a deficiency assessment for 2020, 2018, or 2013? Explain.