Unlocking Opportunities for Small Businesses Act of 2019 This bill requires the past performance of a small business concern to be taken into account in certain situations. Specifically, when a small business previously participated in a joint venture, an agency's contracting officer must consider the past performance of the joint venture when evaluating the small business's offer for a prime contract. In addition, a small business that performed as a first-tier subcontractor for an agency contract may request that the prime contractor submit to a contracting agency a record of past performance, and the agency's contracting officer must consider such record when evaluating an offer by the small business for a prime contract.