The global transition to low-global warming potential (GWP) refrigerants is beginning in a disorderly manner in the U.S. — the world’s most mature HVAC market. In the absence of a federal framework, individual states are beginning to regulate hydrofluorocarbons (HFCs). A handful of states are following Significant New Alternatives Policy (SNAP) Rules 20 and 21, the EPA regulations that were vacated by the courts. California, however, is going much further, proposing regulations for residential and light commercial air conditioning. This state-by-state patchwork of regulations with various timelines is creating serious problems for equipment manufacturers that supply products not to individual states but to a national market. And given that the new low-GWP refrigerants, compared to their HFC predecessors, have different flammability characteristics and require building codes to be updated, this transition must be managed in an orderly manner to prevent serious consequences for consumers.