CFTR, a chloride channel evolved from the exporter member of the ABC Transporter Family, is gated by ATP binding and hydrolysis. Single- channel kinetic data of CFTR have led to a gating model with one-to-one stoichiometry between the gating cycle and the ATP hydrolysis cycle. Recently we found gating transitions which would reflect openings embedded with hydrolysis of more than one ATP molecule―a violation of one-to-one stoichiometry. A new model accentuating energetic coupling between CFTR’s NBDs and TMDs will be discussed.