The National Retirement Risk Index (NRRI) measures the share of American households “at risk” of being unable to maintain their pre-retirement standard of living in retirement. The NRRI is determined by comparing households’ projected replacement rates, retirement income as a percentage of pre-retirement income with target rates that would allow them to maintain their living standards. A recent update shows that, in the wake of the financial crisis and the Great Recession, 51 percent of today’s working households are at risk. A key assumption of the NRRI is that people retire at age 65. Clearly if people worked longer, the percentage at risk would decline. This brief adapts the NRRI calculations to address the question: At what age would the vast majority of households be ready to retire?