This study presents a lightweight metasurface microwave absorption filter (MMAF) designed for low-frequency stealth applications in the L-band. The metasurface is optimized using a genetic algorithm to achieve broadband absorption at subwavelength thickness. The fabricated MMAF consists of a glass fiber-reinforced plastic layer, a metasurface layer, and a dielectric layer with a size of 30 × 30 cm². It maintains a reflection coefficient below −10 dB in the frequency range of 1.01–1.78 GHz. Experiments using small MMAFs measuring 15 × 15 cm² confirmed stable performance after composite molding. In addition, the results from small MMAFs configured in a 2 × 2 array were similar to those of the 30 × 30 cm² structure. These results highlight the potential of the MMAF for scalable deployment on curved or segmented surfaces, expanding its applicability to various stealth platforms.