An image decoding method includes obtaining, from a bitstream, first information indicating a motion vector resolution of a current unit among plural motion vector resolutions including a first motion vector resolution and a second motion vector resolution, and obtaining, from the bitstream, second information indicating whether a merge mode is applied to the current unit or not when the first information indicates the first motion vector resolution. The current unit is decoded based on the merge mode when the second information indicates that the merge mode is applied to the current unit. When the first information indicates the second motion vector resolution, the second information is not obtained from the bitstream. A picture is split into one or more largest coding units, and a largest coding unit among the one or more largest coding units is split into one or more coding units including the current unit.