41 CFR § 105-68.425
When do I check to see if a person is excluded or disqualified?
June 9, 2020
As an agency official, you must check to see if a person is excluded or disqualified before you—
(a) Enter into a primary tier covered transaction;
(b) Approve a principal in a primary tier covered transaction;
(c) Approve a lower tier participant if agency approval of the lower tier participant is required; or
(d) Approve a principal in connection with a lower tier transaction if agency approval of the principal is required.