Systems, devices, and methods are described herein for symmetric merge mode motion vector coding. Symmetric bi-prediction (bi-pred) motion vectors (MVs) may be constructed from available candidates in a merge candidate list for regular inter prediction merge mode and/or affine prediction merge mode. Available MV merge candidates may be symmetrically extended or mapped in either direction (e.g., between reference pictures before and after a current picture), for example, when coding a picture that allows bi-directional motion compensation prediction (MCP). A symmetric bi-pred merge candidate may be selected among merge candidates for predicting the motion information of a current prediction unit (PU). The symmetric mapping construction may be repeated by a decoder (e.g., based on a coded index of the MV merge candidate list), for example, to obtain the same merge candidates and coded MV at an encoder.