We measure the cross-correlation between redMaGiC galaxies selected from the Dark Energy Survey (DES) year 1 data and gravitational lensing of the cosmic microwave background (CMB) reconstructed from South Pole Telescope (SPT) and Planck data over 1289 deg2 . When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.15 . When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.15 . When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.15 m=0.27 6-0.030 0.029 and S8=σ8√{Ωm/0.3 }=0.80 0-0.094 0.090 . We also perform two alternate analyses aimed at constraining only the growth rate of cosmic structure as a function of redshift, finding consistency with predictions from the concordance Λ CDM model. The measurements presented here are part of a joint cosmological analysis that combines galaxy clustering, galaxy lensing and CMB lensing using data from DES, SPT and Planck.