Improper Payments Transparency Act This bill requires the President's annual budget to include specified information regarding improper payment amounts and rates for programs and activities at certain federal agencies. (An improper payment is any payment that should not have been made or that was made in an incorrect amount, including an overpayment or underpayment, under a statutory, contractual, administrative, or other legally applicable requirement.) Specifically, the President's budget must include (1) a narrative description, including a detailed explanation of why any improper payment amounts and rates occurred and related trends for programs and activities; and (2) corrective actions and steps the agencies will take to address improper payment amount and rate issues.