45 CFR §286.120

1. (a)Tribes have the option to exempt families from the established time limits for:
   1. (1)Hardship, as defined by the Tribe, or
   2. (2)The family includes someone who has been battered or has been subject to extreme cruelty.
2. (b)If a Tribe elects the hardship option, the Tribe must specify in its TFAP the maximum percent of its average monthly caseload of families on assistance that will be exempt from the established time limit under paragraph (a) of this section.
3. (c)If the Tribe proposes to exempt more than 20 percent of the caseload under paragraph (a) of this section, the Tribe must include a rationale in the plan.