How to Add a Stepchild to a Health Insurance Plan

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If you have a blended family and confusing health insurance requirements, adding a stepchild to your health insurance plan can be intimidating. However, in most situations where this is possible – and especially with the best health insurance plans – this process can be relatively straightforward.


Best Health Insurance Plans

Marrying a new person you love and combining your families doesn't have to be a bureaucratic headache. Under some health insurance plans, you don't even have to be legally married to claim your partner's children as dependents on your health insurance plan. The key is understanding legal requirements and your health insurance plan's rules and benefits.

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Thanks to the Affordable Care Act (ACA), you can get health insurance through your employer, state or open market. The ACA changed a lot of the rules regarding health insurance, though many of these mandates only affect applicable large employers (ALEs) who have at least 50 full-time employees. However, rules still exist in most cases that require employers and market plans to cover dependents


Taxes and Employers

The IRS recognizes stepchildren as qualifying tax dependents as long as they meet a residency clause. This means that they have to have resided with you for at least six months out of the year. If your stepchildren meet this requirement, as well as all of the other qualifications they must meet to be considered dependents, they also qualify as dependents on state health insurance marketplace plans. Note that for these purposes, you don't have to adopt your stepchildren in addition to marrying their parent.


Employer-sponsored health insurance plans can be a little more flexible and open. The best health insurance plans will accept your partner and their children as dependents even if you are not married to your partner. Many such plans will require an affidavit of domestic partnership and may additionally require your stepchildren's birth certificates. More liberal or inclusive employers will generally not have any additional requirements as long as you faithfully follow other rules in your benefits plan (such as reporting your partner's eligibility for employer coverage).

Adding Your Stepchild to Health Insurance

The first step you must take is checking your employer's health insurance benefits plan brochure to see what kind of family and dependent coverage it offers. details a variety of cases, both legal and domestic arrangements. Then, you will need to adjust your benefits during an enrollment period.


Most health insurance plans will have an open enrollment period around November or near the end of their fiscal year if it differs from the calendar year. During this time, you can change all of your health insurance (and usually other benefits) options, including adding dependents. However, if you want to include your stepchildren during a period of time that falls outside the open period, you may still be able to adjust your benefits as part of a special enrollment period.

Additional Enrollment Information

Special enrollment periods are generally triggered by qualifying life events (QLE) such as death, divorce, marriage, adoption or certain other circumstances. If you have recently married your partner, adopted your stepchildren or entered into a cohabitation arrangement (for certain plans), most employer-sponsored plans will be legally required to give you 30 days within which to make benefits selections. Many employers may extend this to 60 days or more. During a special enrollment period, you will generally be able to make the same selections as you would during an open enrollment period, including adding dependents such as your stepchildren or naming beneficiaries like your partner.


In order to add your stepchildren, you will generally need their Social Security number, date of birth and full legal name at the time of benefit adjustment. This does not have to match your family name. If your stepchildren have a different name or have changed their name later, it can be adjusted at that time – use their legal name at the present moment in time. You may also need your partner's Social Security number and, depending on your plan, a marriage certificate or other proof of partnership.