The low energy level structure of N = 20 32 Mg obtained via β -delayed γ spectroscopy is reported. The level structure of 32 Mg is found to be completely dominated by intruders. An inversion between the 1p-1h and 3p-3h states is observed for the negative parity states, similar to the 0p-0h and 2p-2h inversion for the positive parity states in these N ∼ 20 nuclei. The intruder excited states, both positive and negative parity, are reasonably explained by Monte Carlo shell model calculations, which suggest a shrinking N = 20 shell gap with decreasing Z ispartof: Physical Review C, Nuclear Physics vol:77 issue:3 status: published