The current study aimed to describe formal caregiver burden of nursing assistants in nursing homes. A descriptive, cross-sectional, convergent mixed methods approach identified attributes of formal caregiver burden using phenomenological interviews and established self-report measures. Themes included nursing assistants' experiences of stress, close relationships, extensive assistance of residents, balancing needs and routines, and feeling accomplished. Self-report measures demonstrated moderate stress, moderate caring behaviors, responsibility, and competence. MDS 3.0 results showed moderate cognitive impairment, minimal depressive symptoms, and decreased functional status of residents. The mixed methods synthesis confirmed the presence of five attributes of formal caregiver burden: perceived stress, caring for another, dependency of the older adult, responsibility, and competence. Burnout was not confirmed. Future investigation of attributes among a larger, diverse sample of nursing assistants, residents, and nursing homes will advance knowledge and inform research design and methods of interventions. [Research in Gerontological Nursing, 16(5), 231-240.].