NFL Network Insider Ian Rapoport reported Thursday that the second-year tailback was informed by the NFL he won't be disciplined under the substance abuse policy, per a source informed of the situation.
The news comes after Williams was recently found not guilty of driving under the influence, stemming from a July 2016 arrest.
As a rookie, Williams appeared in 11 games for the Bills, rushing 27 times for 94 yards and a touchdown.
The lack of a suspension is great news for the Bills' backfield. Williams is the favorite for the primary backup role behind LeSean McCoy in Buffalo this season after last year's backup Mike Gillislee left for New England.