Unemployed Worker Lifeline Act This bill extends COVID-19 pandemic unemployment assistance through October 3, 2021. Specifically, the bill extends federal-state agreements under which the aggregate amount of weekly unemployment compensation included an additional $300 in federal pandemic unemployment compensation. The bill increases such weekly amount to $400 for weeks of unemployment ending after March 14, 2021, and ending on or before October 3, 2021. Under current law, this assistance expired on September 6, 2021. The bill also extends through October 3, 2021, the additional $100 in mixed earner unemployment compensation for certain recipients of self-employment income.