Small employers can generally enroll in coverage at any time during the year, either through the SHOP marketplace or in the outside market. During most of the year, insurers may condition enrollment on meeting minimum participation rules and/or contribution requirements. While insurers offering SHOP coverage cannot apply minimum contribution requirements, insurers in the outside market and some state-based health insurance marketplaces may apply such rules. However, insurers must waive these rules from November 15 to December 15 each year and allow groups that don’t meet these rules to enroll in coverage. (45 C.F.R. § 155.725; 45 C.F.R. § 147.104).