This paper considers hybridization of non-orthogonal multiple access (NOMA) and Orthogonal multiple access (OMA) schemes for next-generation cellular networks. The proposed hybrid multiple access (HMA) scheme considers a multi-cell environment that combines NOMA/OMA mode selection as well as channel and power allocation to improve the resource utilization and bandwidth efficiency. The NOMA/OMA modes are categorized into intra-cell and inter-cell OMA and NOMA modes based on an interference map. The HMA focuses on determining the best mode of operation between user pairs to improve the overall sum rate and quality of service (QoS). Results show that the proposed NOMA/OMA mode selection provides superior performance to the conventional OMA schemes without compromising the QoS demands.