LAUSR

We report $^{31}\mathrm{P}$ and $^{29}\mathrm{Si}$ NMR in single crystals of ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2\ensuremath{-}x}{\mathrm{P}}_{x}$ for $x=0.09$ and $x=0.33$. The spectra in the $x=0.33$ sample are consistent with a homogenous commensurate antiferromagnetic phase below ${T}_{N}\ensuremath{\sim}37$ K. The Knight shift exhibits an anomaly at the coherence temperature ${T}^{*}$ that is slightly enhanced with P doping. Spin-lattice-relaxation rate data indicate that the density of states is suppressed for $x=0.09$ below 30 K, similar to the undoped compound, but there is no evidence of long-range order at this concentration. Our results suggest that Si substitution provides chemical pressure and electronic tuning mediated by filling of the $s/p$ shells with minimal electronic inhomogeneity.