The author models the choice between credit cards and home equity lines of credit (HELOCs) within a framework where consumers hold lines of credit as instruments of consumption smoothing across state and time. Flexible repayment schemes for lines of credit induce risk-averse consumers with sufficiently high discount rates to underinsure and hold lines of credit instead as a buffer, even when they have access to full and fair insurance markets. Weighing the fixed upfront fees and higher default costs of HELOCs against the advantages of low and income-tax-deductible interest payments, the author finds a threshold level of potential borrowing belowwhich consumers prefer to use credit cards exclusively. Above that threshold, consumers decide touse HELOCs and consolidate all outstanding credit card debt into them; however, a rising probability of default and the resulting loss of equity in the home will put an upper bound on the potential HELOC borrowing that will prevent full debt consolidation.