When your employer lets you add a spouse to a policy varies by company. It also matters why you’re adding a spouse to health insurance.

If you’re getting married, you can add a spouse immediately if your health plan allows it. Getting married is considered a qualifying life event, which starts a special enrollment period. During the special enrollment period, you can make changes to your health insurance plan, including adding a spouse to coverage.

Another life event that qualifies for a special enrollment period is pregnancy. So, if your wife is pregnant, you can add her to the health plan during a special enrollment period.

Yet another life event that starts special enrollment is when you add a dependent or dependents, such as if your spouse has a child or you adopt a child.

If you don’t add your spouse, children or dependents during a special enrollment period, you’ll have to wait until the annual open enrollment period to enroll or make the change to your health insurance plan.

You can even change the insurance company during a special enrollment period, so make sure to compare insurance plans. You may find another health plan’s benefits and costs, whether through an employer or health insurance marketplace, is a better fit for your family.

Special enrollment periods often last only 30 or 60 days from the qualifying life event. That means you have a month or two to add your spouse after the wedding. If not, you’ll have to wait until open enrollment to make changes to health insurance plans, benefits and coverage.

One other important point — you’ll need to show proof to take advantage of a special enrollment period. So, if you recently got married and want to add your wife or husband to a health plan, you’ll likely have to show your marriage certificate as proof.

If you’re not newly married and don’t have a life event that qualifies for a special enrollment period, you’ll have to wait until the open enrollment period. Employers’ have their own open enrollment period. Check with your company’s benefits department for the dates.