Bb 13b9, 1st inversion (D in the bass)
Also written as Bb13b9/D.
Notes, from the bass up
D (bass)E#G#BGA#
The same notes as Bb 13b9 (D, E#, G#, B, G and A#), rearranged so D is the lowest note. Use it to move between chords with smaller jumps across the keyboard.