Credit bureaus face significant frictions in collecting consumer medical debt liabilities data, which spurred an intense ongoing policy debate. Leveraging novel healthcare costs proxies based on Medicare spending data, we evaluate the impact of hidden medical liabilities on consumer credit scoring and access to credit. We document that the traditional creditworthiness measures underestimate the ex-post default for consumers residing in higher healthcare costs markets. Consumers in high-healthcare-cost CBSAs are 37.6% more likely to default than those in low healthcare-cost CBSAs. These effects are more pronounced among higher risk consumers, those with low credit scores and high DTIs. Lenders internalize these biases and impose higher mortgage rejection rates in high-healthcare-cost CBSAs, particularly for riskier applicants. These effects intensify following a policy shift that partially removed medical liabilities from credit reports without affecting consumer balance sheets. Our findings suggest that limiting the flow of medical liabilities data undermines the predictive accuracy of standard credit metrics, impairs the information value of credit bureau outputs, and leads to less efficient credit allocation.