The present disclosure provides T-cell modulatory multimeric polypeptides comprising two different immunomodulatory polypeptides, at least one of which is a variant immunomodulatory polypeptide. The present disclosure provides nucleic acids comprising nucleotide sequences encoding the T-cell modulatory multimeric polypeptides, and host cells comprising the nucleic acids. The present disclosure provides methods of modulating the activity of a T cell; the methods comprise contacting the T cell with a T-cell modulatory multimeric polypeptide of the present disclosure.