Husband 67 may go on Long Term work Disability Sept 13yh13

If my husband goes on Long Term Disability on Sept 13. He will be forced to go on Disability and Medicare. Due to him being 67 can he keep a 18 month Cobra. He is currently signed up for Part A medicare but it's not activated yet. If he gets termination at work and forced to Medicare he needs his Cobra primary I sureness to pay foe Chemo and other treatments. Who do I talk to in Maryland to get this Info