I work for a company that has health insurance. I did not sign up when I was supposed to, because I am a single mother with two kids, and the insurance was going to cost me $250 a month. I am now a manager with that company, and I can finally afford the insurance, but they tell me I have to wait for "open enrollment." The last time they had open enrollment was more than two years ago, and they don't know when they will have it again. Shouldn't I be able to sign up? I'm willing to take a physical.

S.P.

Open enrollment and eligibility for group health plans is governed by several forces -- federal and state law, employer practices and insurance provisions. According to the law, coverage under small-group health insurance is guaranteed. That is, a plan may not decline to insure any individual eligible for the plan who elects to be covered. In addition, a plan may impose a 12-month exclusion period for pre-existing conditions, but must give credit to a person with previous coverage. If a new employee elects to be covered during an eligibility period and has had, say, five months of previous coverage, that person needs only satisfy a seven-month exclusion. If the person had 12 months or more of coverage, the plan may not impose an exclusionary period. Once the exclusion is satisfied and the employee maintains continuous coverage, he or she will not be subject to another exclusion.
The law treats "late enrollees" differently. A person who declines coverage during the initial eligibility period may be required to satisfy an 18-month exclusion when electing to be covered at a later date.

Employers and insurers determine other aspects of employer-based coverage. For example, an insurance company may require a certain number or percentage of employees to participate in the plan for the group to qualify for insurance. The insurer may also require that the employer pay a certain percentage of the premium. These requirements are intended to ensure that the group is committed to the coverage.

The employer may set eligibility standards, such as a waiting period and open enrollment. The waiting period is the initial period of employment during which a new employee is not eligible for such benefits as health insurance. There may be separate waiting periods for participation in a pension plan, profit sharing, etc. Open enrollment is a limited period of time during which an existing employee may elect to participate in a health plan or add dependents to existing coverage. During open enrollment, there is no proof of health status required.

Normally, an employer grants an annual open enrollment period, usually in January. During this time, employees are given the opportunity to change pension options, flexible spending arrangement amounts, and even health-plan options. If an employee has been married in the past year, this is the opportunity to enroll the new spouse in the health plan. Those employees electing to participate in a company health plan during an open enrollment may be required to satisfy an 18-month pre-existing condition exclusion period as a late enrollee. This is normally the consequence of failing to elect coverage during the initial period of eligibility.

When health insurance is available at a cost of $250 a month, especially for a single mother with two children, it is probably wise to participate. If the company only rarely allows open enrollment, the next chance may be a long time in coming. Meanwhile, one illness can cost more than a year's worth of premium. One broken bone can be quite a financial setback. A visit to an emergency room on a Saturday night can be devastating. Even when it is necessary to sacrifice in order to be insured, it is worth it.

In your case, you should find out just what your company's enrollment policy is. Speak to the benefits manager or human resources personnel. You may discover that the company has regular periods of open enrollment for adding dependents and spouses to the coverage. Find out whether you can be added to the plan with proof of insurability. And the next time there is an open enrollment, be sure to participate.