I am trying to create a validation rule that should be basic but is not firing for me.

I have a picklist called  Prefix__c that has several values in it,

I want to fire if PICVAL is = to "Maintenance (CMT)", or "Maintenance Renewal (CMR)" and the custom date field of Maintenance_Start_Date__c is blank so that the date field becomes required,

This is what I have in place now, that is not working

AND(OR(ISPICKVAL(Prefix__c, "Maintenance (CMT)"),ISPICKVAL(Prefix__c, "Maintenance Renewal (CMR)")),ISBLANK(Maintenance_Start_Date__c))

Any assistance would be appreciated..

I am trying to create a validation rule that should be basic but is not firing for me.

I have a picklist called  Prefix__c that has several values in it,

I want to fire if PICVAL is = to "Maintenance (CMT)", or "Maintenance Renewal (CMR)" and the custom date field of Maintenance_Start_Date__c is blank so that the date field becomes required,

This is what I have in place now, that is not working

AND(OR(ISPICKVAL(Prefix__c, "Maintenance (CMT)"),ISPICKVAL(Prefix__c, "Maintenance Renewal (CMR)")),ISBLANK(Maintenance_Start_Date__c))

Any assistance would be appreciated..