Hyponatremia is an important medical and economic problem that is pronounced in diverse patient populations. The common electrolyte disorder is associated with poor clinical outcomes, including high mortality and increased length of stay, which translate into excess resource utilization and costs. Measurement of osmolality is the first step in determining the etiology of hyponatremia. Management of hyponatremia remains suboptimal and critical testing is not routine despite published guidance on diagnosis of the condition, clear associations with poor outcomes, increased medical costs, and significant evidence that correction improves outcomes. Osmolality is a highly cost-effective test that is proven and medically necessary in the management of hyponatremia. Addressing underutilization of the low-cost test, including education on its interpretation, would grant physicians critical information they need to mitigate unfavorable outcomes and enable hospitals to recover a significant portion of the $1.14 billion in potentially avoidable costs associated with electrolyte disorders in the U.S. alone.