This paper presents the design of a compact triple-band artificial magnetic conductor using stacking of the complementary structure. The proposed triple-band complementary AMC is formed by combining the cross-shaped structure with three stubs of different lengths at each arm on one dielectric slab and its complementary geometry on the other dielectric slab. The proposed AMC provides the three 0° degree reflection phase frequencies at 2.45 GHz, 3.5 GHz, and 5.99 GHz with a ±90° reflection phase bandwidth of 0.2 GHz, 0.17 GHz, and 0.94 GHz, respectively. The unit cell size is 13 mm×13 mm (0.1λ 0 ×0.1λ 0 ), where λ 0 is the wavelength at the lowest resonance frequency of 2.45 GHz. The proposed structure is insensitive to incident polarization and angles due to the four-fold symmetry of the unit cell. In addition, on rotating the complementary structure, the AMC unit cell exhibits the two closely spaced reflection phase frequencies.