<p>18Ni300 maraging steel (MS) is a high-strength, ultra-low carbon steel widely utilized in aerospace, tooling, and military applications due to its enhanced mechanical properties. The present investigation examines the effect of scanning strategies, powder reuse, and heat treatment on the microstructural evolution and mechanical performance of MS built using laser powder bed fusion (LPBF). Two distinct scanning strategies—stripes and chessboard, were used during fabrication with fresh and recycled powders, to comparatively evaluate their density, residual stress, and tensile properties. Experimental results revealed that the stripes scanning strategy yields finer cellular grains and higher tensile strength due to a more efficient heat dissipation pattern. The use of recycled powder slightly enhances tensile strength, which can be attributed to increased oxygen content affecting particle flowability and microstructure refinement. Post-processing heat treatment resulted in enhancement of tensile properties, aided by the formation of intermetallic nano-precipitates, but with reduced elongation. The results provide valuable insights into optimizing processing parameters for LPBF-fabricated MS components to achieve superior mechanical performance and enable the economical reuse of recycled powder.</p>