Action shall be taken on all changes reported during a household's certification period in accordance with the timeliness standards set forth in 106 CMR 366.120. Households shall be notified whenever their monthly SNAP allotment is changed as a result of changes in their public assistance grant or whenever their SNAP certification period is shortened to reflect changes in household circumstances (see 106 CMR 365.170: Department Action on Reported Changes). In cases jointly processed by SSA and the Department (see 106 CMR 361.190: Handling Applications for Pure SSI Households) in which the SSI determination results in denial, the worker shall send the household a notice of termination if the worker believes the household's SNAP eligibility or benefit level may be affected. The notice shall advise the household that its certification period will expire in the month that follows the month in which the notice is sent and that it must reapply if it would like to continue to receive SNAP benefits. The notice shall explain that the household's certification period is expiring.