There's none in the stores and little or nothing online.
I have an easier time finding 16 & 28 gauge ammo.
Plenty of 20 ga. shells in Scheels Missoula today.
Any of it in lead shot 5s or 6s in field, high base, or 3" in those? Nobody has them that I can find, at least here or online.
I'm glad I also shoot a 16 gauge.