Whether Washington and Beijing cooperate under the Biden administration depends heavily on whether they reach an understanding on how to approach the DPRK. This was a touchstone for prospects of cooperation under George W. Bush and Barack Obama as well as during the first year of the Trump administration. China is watching to see what US policy toward North Korea’s denuclearization will be, while the Biden camp will be closely attentive to how China will respond. From 2018 through 2020 there was less cooperation on North Korea than during recent periods, removing one backstop of diplomatic interactions. While some expect this to change under Biden, it remains unlikely that the atmosphere of close consultations will be restored, both because of loss of trust in the overall relationship and of sharper divergence in approaches to the DPRK. This article points to barriers to cooperating on North Korea.