Special assessment for a co-op in NYC

I receive the STAR credit and the SCHE (senior citizen) exemptions every year, posted on my June maintenance bill. 

I also receive a Special Assessment. I understand that Co-op board can charge residents for this assessment to offset building capital projects or other expenses not in the regular operating budget. 

A neighbor received the STAR credit and was not eligible for the SCHE exemption. He was NOT charged a special assessment.

Is it age discrimination to charge senior citizens for a special assessment, and not anyone else?