The author studies the welfare implications of adjustment programs supported by the International Monetary Fund (IMF). He uses a model where an endogenous borrowing constraint, set up by international lenders who will never lend more than a debt ceiling, forces the borrowing economy to always choose repayment over default. The immediate potential welfare cost of joining a program is driven by IMF conditionality: to be able to borrow from the IMF, the country has to submit to limits on the consumption of public goods. The benefits derive from the additional borrowing from the IMF (at a lower interest rate) and/or through a ?catalytic effect? on private loans, which facilitates consumption smoothing over time. Simulations of the dynamic model in two institutional environments?with and without the IMF?are compared. Results indicate that when conditionality forces the country to save more, at a cost that does not prevent it from joining an IMF program, the resulting lower probability of default can induce private lenders to relax their borrowing constraints. Based on a calibration of the model for the Brazilian economy, the overall welfare gains associated with IMF programs are relatively small.