 This study examined the relationship between multi-morbidity and spending from two distinct perspectives. One, quantifying spending on different disease combinations. And, two, assessing how spending on a single disease is changes when we consider the contribution of multi-morbidity, additional slash reduced spending that could be attributed in the presence of other chronic conditions. The results showed that chronic kidney disease and ischemic heart disease were associated with high-spending-portreated case, high-observed prevalence, and contributing the most to spending when in combination with other chronic conditions. This article was authored by Angela Y. Chang, Dana Bryaska, and Joseph L. Dealman.