Busyness (the density of activities) and daily routine (patterns of organizing time) are two understudied factors that likely impact medication-taking behaviors. We examined the association between busyness and routine with medication adherence (MA) in 405 older adults with adequate cognition using multivariable models. The final model included an interaction term between daily routine and busyness. MA scores (measured by the ASK-12, higher scores mean more barriers to adherence) were higher for individuals reporting low and moderate levels of daily routine versus those with high daily routine. MA scores were higher for individuals reporting moderate and high busyness versus those reporting low busyness. The busyness/routine interaction term was significant for MA; among highly busy individuals, those with high daily routine had lower MA scores than those with low routine. A daily routine may be a modifiable factor for improving MA among older adults, particularly among those with busy lives.