Scholars have argued that immigrants’ trust in institutions is the result of the exposure to host-country institutions but also shaped by past experiences in the country of origin. These experiences create a “home-country point of reference,” a political/institutional memory that becomes the relevant comparison for any political/institutional interaction in the host country. We develop further this concept and unpack its key determinants—the age at migration and the historical conditions of the home country at the specific time of migration. Only those immigrants who were too old to forget the historical and contextual features of the country-of-origin institutions at the time of migration will rely on this comparison when interacting with institutions in the host country. Across time, there is both a continuous positive/negative accumulation of trust for the host-country institutions among those with less/more democratic points of reference. We examine immigrants’ political trust using survey evidence from Israel.