A system for allowing a telephone subscriber to selectively block incoming calls for selected time periods or during programmed time intervals. A subscriber may pre-program a time interval in minutes, or a time period (start time and end time) for which some or all incoming calls are to be blocked. The subscriber may assign caller numbers or personal identification numbers to one of a plurality of tiers of access. The subscriber may enable the call blocking system for selected access tiers. An emergency access tier may be provided to insure emergency calls are not blocked by the system.