0001530249 2026-05-21 2026-05-21 false 0001530249 8-K 2026-05-21 FS BANCORP, INC. WA 001-35589 45-4585178 6920 220th Street SW Mountlake Terrace WA 98043 425 771-5299 false false false false Common Stock, par value $0.01 per share FSBW NASDAQ false