Cognitive impairment and dementia have rising prevalence and impact the health care utilization and lives of older adults. Receipt of low-value (LV) care and underutilization of high-value (HV) care by individuals with these cognitive disorders may have negative consequences for patient health, health system efficiency, and societal welfare. Evidence on health care value among cognitively impaired individuals is limited; we thus ascertained receipt of LV and HV health care in older adults with normal cognition, cognitive impairment without dementia (CIND), and dementia. Retrospective cohort study of Health and Retirement Study data linked to Medicare claims (1996-2018). We examined the association between cognitive decline and the receipt of 5 LV and 7 HV services vs individuals with no change in cognition. Receipt of LV care ranged from 4% to 13% regardless of cognitive status. Cognitive decline (from unimpaired to either CIND or dementia) was associated with decreased probability of receipt of 1 LV service (colorectal cancer screening at 85 years and older [5-percentage-point reduction; P = .047]) and 3 HV services (glucose-lowering drugs [7-percentage-point reduction; P = .029], statins [32-percentage-point reduction; P = .045], and antiresorptive therapy [61-percentage-point reduction; P = .019]). LV service receipt is wasteful and may be harmful, but it was not consistently associated with cognitive status. Lack of HV care for those with cognitive impairment could be a missed opportunity to improve well-being or reduce preventable adverse events. Our results suggest opportunities for improving the quality of care received by all older adults, including those with cognitive impairment.