A minor 9th chord is created by adding a 9th degree to any minor7th chord. For example, a Cm9 chord contains the notes C, Eb, G, Bb and D (1, b3, 5, b7 and 9). Here are some common open minor 9th chord shapes.
Cm9
Dm9
Em9
Fm9
Dbm9
Ebm9
F#m9
Gm9
Abm9
Am9
Bbm9
Bm9