IT’S ESTIMATED THAT THE CONTEMPORARY SYSTEM of municipal bond ratings costs issuers over $2 billion annually. Fees paid to rating agencies directly account for about $500 million of this total. The greater burden on issuers arises from the relatively harsh ratings that agencies assign municipal bonds vis-à-vis. other instruments. These costs take the form of additional interest paid to investors and purchases of municipal bond insurance intended to reduce this interest burden. Since defaults by rated municipal bond issuers are so rare, and since defaulting issuers can usually be identified ahead of time by accounting ratios and economic indicators, I conclude that significant cost savings are possible by replacing the current rating system with model-based assessments that yield higher ratings overall while still differentiating at-risk issuers.