For our purposes here today, I'm going to set the parameters for standard/expected sizing at around 32-44 inch bust measurements. Many of us know that we cannot always expect even this much inclusivity, but what I'm looking for is an extended level of inclusivity. It's about time!
Anna Allen :: patterns sizes up to 22
Blueprints :: busts up to 50 inches
Cashmerette :: sizes 12-28
Closet Case :: sizes up to 20 + extending (take the survey)
Colette + Seamwork :: up to size 26
Deer & Doe :: French sizes up to 52
Elbe Textiles :: currently working to extend size range up to a 52 inch bust
Fancy Tiger :: sizes up to 20
Grainline :: currently working to extend up to size 30 (participate in their survey)
Leisl + Co :: up to size 20
Helen's Closet :: currently includes sizes up to 22 :: working to extend up to size 30
Made by Rae :: bust sizes up to 51 inches
Marilla Walker :: bust sizes up to 49 inches
Megan Nielsen :: newly updated patterns up to size 30
Muse :: up to 50 inch bust + D cup
Named :: up to size 18
Paper Theory :: up to size 20
P4P :: up to 54 inch bust
Sew House Seven :: up to size 20
Sew Liberated :: up to size 24
Schnittchen :: up to 53 1/2 inch bust
100 Acts of Sewing :: up to 50 inch bust
Sew DIY :: up to 51 inch bust
Wiksten :: the newest pattern includes sizing up to size 22
For lots more wonderful independent pattern designers (not exhaustive by any means)...many more of which may join these ranks in the future...this list. Also more plus sized mentions here.
Love,
Jane