On April 19, 2019, USCIS issued a policy alert that it was modifying its Policy Manual to clarify that violations of controlled substance laws are conditional bars to establishing good moral character (GMC) for naturalization. This is true even if the conduct would not be an offense under state law. This clarification became necessary in light of the recent trend toward state legalization or decriminalization of marijuana, which remains illegal under federal law.
As a result of its federal prohibition, a conviction or admission of conduct involving marijuana may still be a bar to establishing GMC and, thus, prevent naturalization.