Disclosed is a method and system of imposing a policy rule for excessive usage in an access network. According to the disclosure, a policy enforcement point (PEP) may detect that usage by a given client device is threshold high and responsively request, from a policy decision point (PDP), a policy directive that specifies a policy rule to apply to the given client device. However, thereafter, the PEP may determine that the requested policy directive has not been received from the PDP and then responsively apply, to the given client device, a default policy rule for threshold-high usage.