Farm Labor Expansion Act of 2020 or the FLEX Act This bill allows farmers a new tax credit for 40% of the first-year wages paid to eligible replacement workers. The bill defines an eligible replacement worker as any individual who began a period of unemployment after March 27, 2020, and was receiving unemployment compensation during such period, and performs for the employer substantially the same job functions as temporary agricultural workers. The bill limits the amount of wages taken into account for any employee for purposes of the credit to $25,000 for all taxable years and terminates the credit two years after the enactment of this bill.