OBJECTIVES:  Little is known about the effect of caregiving for people with multiple myeloma (MM) on work productivity, activity impairment, depression and anxiety. This study examined the burden on caregivers providing care to adults with MM. METHODS:  A cross-sectional survey of 145 MM caregivers recruited through the Light Speed Research panel was conducted. The IRB-approved survey assessed patient and caregiver demographic characteristics, hours of provider care, and MM treatment. The study assessed caregiver burden using validated instruments including, the Work Productivity and Activity Impairment (WPAI) questionnaire, the Patient Health Questionniare-9 (PHQ-9; range 0-27, higher scores indicate greater depression severity) and Generalized Anxiety Disorder-7 (GAD-7; range 0-21, higher scores indicate greater anxiety severity). The results are summarized using descriptive statistics. RESULTS: Among the 145 caregiver respondents, 60.7% (n=88) were female and the mean age was 51.9 (SD=12.6) years. Of these, 72.4% were White, 78.6% married, and 65.5% employed. Caregivers, on average, had been providing care to the MM patients for 4.1 years (range=0.2-27.5), and reported providing 31.5 (SD=35.8) hours of care per week. Patient characteristics were as follows: Diagnosed 5.1 (SD=6.6) years prior to study enrollment, 44.8% female, 59.9 (SD=13.9) years old, on a multiple-drug regimen (1.9 drugs (SD=1.0)) for MM. A total of 30.3% were on their third or later treatment regimen. In univariate analyses, caregivers reported a mean (SD) absenteeism from work due to impairment of 14.5% (14.3%), impairment while at work (presenteeism) of 47.0% (31.7%), overall work impairment of 51.5% (33.1%), and activity impairment of 44.4% (31.3%) in the past 7 days. Mean (SD) scores on the GAD-7 and PHQ-9 were 6.6 (4.9) and 7.6 (5.9) respectively. CONCLUSIONS:  There is a significant caregiver burden associated with caring for a person with MM, impacting productivity and daily activities. Caregivers also experience mild depression and anxiety symptoms.