Housing assistance in Missouri for elderly with high medical bills?

My parents' monthly income puts them over the limit for low income housing however, most of their income goes towards medical bills (even with supplimental insurance to medicare). Does anyone know of a housing program in Missouri that takes medical expenses into consideration? I called several section 8 places but they only look at income amt. I checked with HUD and they said some section 8 places do take this into consideration. Thank you!