OBJECTIVE Chervoneva et al. (2020) developed an abbreviated score (sMNAS-9) derived from full modified Finnegan MOTHER NAS scale (MNAS) for evaluating severity of NOWS. We sought to develop NOWS treatment algorithms for clinical decision rules based on scores utilizing the shorter sMNAS. METHODS This was a retrospective study of 373 infants with NOWS scored with MNAS and treated with morphine between 2007 and 2016. The infants were randomly split into training/test sets. The training set was used to derive optimized cutoff values for sMNAS-9 scores. The independent set evaluated the sMNAS-9 clinical decision rules based on full MNAS in NOWS morphine and buprenorphine treatment algorithms. RESULTS Clinical decision rules based on sMNAS-9 yielded sensitivities of 88% or higher and specificities of 85% or higher for predicting the respective rules based on full MNAS. CONCLUSIONS The sMNAS-9 scoring instrument is expected to yield similar clinical decisions in treatment of NOWS.