(a) For a residential lease of tribal land, unless the lease provides otherwise, no periodic review of the adequacy of rent or rental adjustment is required if:

1. (1) The tribe states in a tribal certification or authorization that it has determined that not having rental reviews and/or adjustments is in its best interest; or
2. (2) The lease is for housing for public purposes.

(b) For a residential lease of individually Indian owned land, unless the lease provides otherwise, no periodic review of the adequacy of rent or rental adjustment is required if:

1. (1) The lease is for housing for public purposes;
2. (2) The term of the lease is 5 years or less;
3. (3) The lease provides for automatic rental adjustments; or

4. (4) We determine it is in the best interest of the Indian landowners not to require a review or automatic adjustment based on circumstances including, but not limited to, the following:

   1. (i) The lease provides for payment of less than fair market rental; or
   2. (ii) The lease provides for most or all rent to be paid during the first 5 years of the lease term or before the date the review would be conducted.

(c) If the conditions in paragraph (a) or (b) of this section are not met, a review of the adequacy of rent must occur at least every fifth year, in the manner specified in the lease. The lease must specify:

1. (1) When adjustments take effect;
2. (2) Who can make adjustments;
3. (3) What the adjustments are based on; and
4. (4) How to resolve disputes arising from the adjustments.