This experiment introduced a new set of microfinance products based on planning and reminders to help microfinance borrowers build their savings. In collaboration with Guatemala's largest public-sector bank, Credito Hipotecario Nacional (CHN), researchers randomized the deployment of new behaviorally motivated financial products across the bank's entire microfinance clientele. Three financial products were randomized across the 20 microfinance branches of CHN. All clients who applied for a microfinance loan were offered one of the three microfinance products, depending on which product their bank branch had been assigned. Clients who were part of the control group (Basic Savings) received a savings promotion (brochure plus verbal reinforcement) and an explanation of contract terms, and were offered the chance to open a savings account at the time of loan disbursement. In the first treatment arm (Open Treatment), clients taking new loans were offered the opportunity to define a monthly savings deposit that they would then be prompted to make each time they made a loan payment. In the second treatment arm (Default Treatment), clients were offered this same option, but told that the bank would set the default deposit amount at 10% of the loan payment, unless clients decide to change it.