Final answer:
An insurer must provide a minimum of 30 days as a special enrollment period after marriage for an employee to add a new spouse to a small group health plan.
Step-by-step explanation:
After the date of marriage, an insurer is required to provide a minimum period of time for an employee to add a new spouse to a small group health plan. This period is known as a special enrollment period which typically aligns with provisions under the Health Insurance Portability and Accountability Act (HIPAA).