Immune checkpoint inhibitors (ICIs) have become a cornerstone in cancer treatment. With high treatment costs and an increasing number of young and low-income patients with cancer, there is a need to determine the current spending and utilization of ICIs in a real-world population. The objective of this study was to outline the drug spending, utilization, and price trends of ICIs for US Medicaid programs from 2011 to 2021. A retrospective descriptive analysis was conducted using the Medicaid State Drug Utilization pharmacy summary files managed by the Centers for Medicare and Medicaid Services. Six ICIs for this study include ipilimumab, pembrolizumab, nivolumab, atezolizumab, avelumab, and cemiplimab. Yearly reimbursement and prescription numbers were calculated for six ICIs billed through Medicaid between 2011 and 2021. The average spending per prescription was calculated as a proxy for drug prices. Overall spending and utilization on ICIs have risen exponentially over the past decade. Between 2011 and 2021, expenditures increased from $2.8 million to $4.1 billion. Utilization increased from 94 prescriptions to 462,049 prescriptions in 2021 with six ICIs. The average spending per prescription, or average drug price, decreased 70%, from $29,795.88 in 2011 to $8914.69 in 2021. Spending on and utilization of ICIs have increased dramatically over the past decade. These findings shed new light on the impact of ICIs on state Medicaid programs and may provide insight into potential cost drivers that need to be addressed through policy.