The Research and Development Survey (RANDS) is a series of cross-sectional surveys using probability-sampled commercial survey panels. The fourth round of RANDS (RANDS 4) was administered by NORC at the University of Chicago using the AmeriSpeak Panel from July 17, 2020 to August 24, 2020. RANDS 4 contained the embedded probe questions and experiments as in previous rounds of RANDS, but had an emphasis on disability and the use of opioid pain relievers. RANDS 4 has a known survey sampling design and can be used to produce nationally and sub-nationally representative estimates.