Start Making Adjustments and Require Transparency in Cocaine Sentencing Act or the SMART Cocaine Sentencing Act This bill reduces the federal sentencing disparity between drug offenses involving crack cocaine and powder cocaine. Currently, different threshold amounts of crack cocaine and powder cocaine (e.g., 28 grams of crack cocaine and 500 grams of powder cocaine) trigger the same statutory criminal penalties. This bill reduces the federal sentencing disparity by altering the threshold amounts of crack cocaine and powder cocaine that trigger statutory criminal penalties. Specifically, the bill increases the threshold amounts of crack cocaine (e.g., from 28 to 160 grams) and decreases the threshold amounts of powder cocaine (e.g., from 500 to 400 grams) that trigger statutory criminal penalties. The changes may apply retroactively, but only if the Department of Justice (DOJ) certifies that the sentence of a defendant should be reduced. The bill requires DOJ to review and report on various data related to crack cocaine and powder cocaine, including individual dosage amounts, addictiveness, and associated violence. Additionally, the U.S. Sentencing Commission must report publicly on cocaine offenses and offenders, including trends in cocaine trafficking patterns, price, and use; the interaction of state penalties with federal prosecutorial decisions; and federal case law developments related to federal cocaine sentencing.