A method at a multicast router for reducing congestion in an access network caused by oversubscription of multicast groups, wherein the multicast router is coupled with a multicast enabled layer 2 device that is coupled with a source of multicast data traffic for the multicast groups and maintains multicast membership state of the multicast groups, the method comprising the steps of: receiving a first multicast membership report message that indicates that a multicast host of a subscriber has joined a first multicast group, wherein the multicast host is one of a set of one or more multicast hosts (132 A-M) of the subscriber, and wherein one or more of the set of multicast hosts are a member of a set of one or more second multicast groups; calculating an amount of bandwidth currently being attributed as being used by the subscriber based on at least an amount of bandwidth that is required for the first multicast group and the set of second multicast groups; and responsive to determining that the amount of bandwidth currently being attributed as being used by the subscriber exceeds its allowed bandwidth limit due to the multicast host joining the first multicast group, switching from periodically transmitting multicast membership general query messages to the set of multicast hosts to transmitting one or more multicast membership group-specific query messages to those of the set of multicast hosts that are a member of the set of second multicast groups that do not request membership reception state of the first multicast group to impede the multicast host from refreshing its membership to the first multicast group to cause the multicast membership state of the multicast host for the first multicast group in the multicast enabled layer 2 device to expire and the multicast data traffic for the first multicast group from being transmitted to the multicast host; whereby congestion is reduced in the access network by impeding the multicast host of the subscriber from refreshing its membership state to the first multicast group that caused the subscriber to exceed its allowed bandwidth limit. receiving a first multicast membership report message that indicates that a multicast host of a subscriber has joined a first multicast group, wherein the multicast host is one of a set of one or more multicast hosts (132 A-M) of the subscriber, and wherein one or more of the set of multicast hosts are a member of a set of one or more second multicast groups; calculating an amount of bandwidth currently being attributed as being used by the subscriber based on at least an amount of bandwidth that is required for the first multicast group and the set of second multicast groups; and responsive to determining that the amount of bandwidth currently being attributed as being used by the subscriber exceeds its allowed bandwidth limit due to the multicast host joining the first multicast group, switching from periodically transmitting multicast membership general query messages to the set of multicast hosts to transmitting one or more multicast membership group-specific query messages to those of the set of multicast hosts that are a member of the set of second multicast groups that do not request membership reception state of the first multicast group to impede the multicast host from refreshing its membership to the first multicast group to cause the multicast membership state of the multicast host for the first multicast group in the multicast enabled layer 2 device to expire and the multicast data traffic for the first multicast group from being transmitted to the multicast host; whereby congestion is reduced in the access network by impeding the multicast host of the subscriber from refreshing its membership state to the first multicast group that caused the subscriber to exceed its allowed bandwidth limit.