In 2018, 74.3% of Medicare fee-for-service beneficiaries with CKD were enrolled in a Medicare Part D plan, which was slightly more than those without CKD (70.4%) (Figure 7.1). Qualification for the low-income subsidy (LIS) was more common among Part D beneficiaries with CKD (34.4%) than among beneficiaries without CKD (31.5%), a pattern that was consistent across categories of race and age (Figure 7.3). LIS qualification was much higher among Asian (76.1%) and Black (62.2%) than White (27.5%) Part D beneficiaries with CKD (Figure 7.3). Between 2009 and 2018, total Medicare Part D spending rose by 188% in those with CKD ($4.6 to $13.1 billion) and by 37% in those without CKD ($39.5 to $54.2 billion). Those with CKD accounted for 10% and 20% of all Part D spending in 2009 and 2018, respectively (Figures 7.5 and 7.6). Per person per year Part D spending also increased in this period, by 16% in those with CKD and by 6% in those without CKD (Figure 7.5). Thus, the increase in Part D costs for the CKD population was driven by a combination of growth in the CKD population and higher costs within the population. In 2018, per person per year Medicare Part D spending was 1.7 times higher for those with CKD ($5392) than for those without CKD ($3118) (Figure 7.7). Among those with CKD, per person per year Medicare Part D spending was approximately 3 times higher in those with the LIS ($9772) versus those without the LIS ($3291), whereas out-of-pocket costs were approximately 11 times higher in those without the LIS ($960) versus with the LIS ($86) (Figure 7.8). Overall, Medicare spending on medications was highest in Black and lowest in White beneficiaries. However, considering those with and without LIS separately shows that spending was relatively similar for Black and White beneficiaries with and without LIS (Figures 7.7 and 7.8). The most common drug classes, each prescribed in more than half of Part D enrollees with CKD in 2018, included statins, antibiotics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and beta blockers (Table 7.2). Total Medicare Part D spending was highest for insulin, followed by cancer and adjunctive agents, direct oral anticoagulants, and dipeptidyl peptidase-4 inhibitors (Table 7.3). From 2009 to 2018, opioid prescriptions declined substantially, but were consistently higher in those with CKD than those without CKD (Figure 7.10). Diagnosis of opioid use disorder (OUD) increased 3-to 4-fold between 2009-2011 and 2016-2018. Use of medication-assisted treatment (MAT) was low (Figure 7.12). Between 2009 and 2018, there were varying trends in prescriptions for non-opioid medications sometimes used for pain: prescriptions decreased for benzodiazepines, increased for gabapentinoids, and fluctuated for muscle relaxants (Figure 7.13).