The contracting officer must:

(a) Determine that the recipient's cost sharing contributions meet the criteria for cost sharing and determine values for them, in accordance with §§603.530 through 603.555. In doing so, the contracting officer must:

(1) Ensure that there are affirmative statements from any third parties identified as sources of cash contributions, and

(2) Include in the award file an evaluation that documents how the values of the recipient's contributions to the funding of the project were determined.

(b) Judge that the recipient's cost sharing contribution, as a percentage of the total budget, is reasonable. To the maximum extent practicable, the recipient must provide at least half of the costs of the project, in accordance with §603.215.