I added a subtype to an existing list of subtypes for a subject feature class and is not showing up in my Create Features Tree. The original Feature class subtypes do appear except for the one created at a later date.

[AlejandroDe_la_Rosa]

Please see attached image below. Subtype Code 15, "Flush Valve w Gate Valve", does not appear on the Feature Class Tree on the right of the image. 

[Asrujit_SenGupta]

Did you close and reopen ArcMap and then check?

Add the Feature Class to a new MXD and then check if the new one shows up...

[AlejandroDe_la_Rosa]

Closing and re-opening arcmap did not help. adding the modified feature class to the mxd did work. The original feature class needs to be erased. 

[AbdullahAnter]

Could you check by open attribute table and edit any value in the subtype field , see the menu if the new value included.

if so

add new this template by open organize templates, then New template and add all template.as the following picture.