Welcome to the March 2026 issue of the Artificial Intelligence and Data Science for Communications series of the Institute of Electrical and Electronics Engineers (IEEE) Communications Magazine. As 5G systems evolve and 6G networks approach, artificial intelligence (AI) is shifting from enhancement to foundation, shaping how networks are designed, operated, and secured. This issue assembles nine papers with a common aim: translating recent AI advances into systems that are reliable, efficient, and trustworthy at scale. Readers will find tools to curb hallucinations in large language model (LLM)-based assistants, verify AI actions in the radio access network (RAN), automate health monitoring with machine learning operations (MLOps), build communications-native foundation models, orchestrate multi-agent services at the edge, and create the data fabric AI-native networks require. We also include practical guidance for model generalization in channel state information (CSI) feedback and for embedding intelligence in non-terrestrial systems, both for interactive media over low Earth orbit (LEO) satellite networks and real-time traffic prediction in large constellations.