The Family and Medical Leave Act, FMLA, was passed into law in 1993 to provide limited unpaid time off to employees in case they are sick, or to provide for a sick family member. When the period of leave ends, there is no defined policy and several things can happen, depending on the specific situation.
The FMLA provides up to 12 weeks of unpaid time for an employee to deal with medical concerns for either himself or a family member. It also allows you to take leave to care for a newborn child, or a child who has just been placed for adoption. Your employer may also require you to take any paid vacation or sick time that you have accrued as part of your leave. At the end of the 12 weeks, your employer must allow you to return to your job, or a job with equal pay and benefits. If your company designates you as a key, salaried employee, they can exempt you from the FMLA.
After the 12 weeks of medical leave is over, your employer may allow you to continue your leave of absence. This depends on the individual company and may also depend on how they view you as an employee. If you hope to continue your leave at the end of 12 weeks and stay employed by the company, you may want to communicate your wishes as soon as possible, and try to work out the details. If your employer voluntarily allows you to continue leave, they may want you to pay for the entire cost of your health benefits if you continue them.
At the end of the 12 weeks of medical leave under FMLA, your employer is not required to keep you on their payroll. Your employer will probably provide you notice at the end of the 12 weeks that they have terminated your employment if that is the way they choose to proceed. Communication with your employer is critical if you want to keep your job, but will require more time.
You may elect to resign from your position at the end of the medical leave. You may also want to resign if you have a persistent illness, and you are going to have long-term disability insurance benefits available to you, or other government benefits. If the situation is long term, you may choose to resign to bring closure to that part of your life, so that you may move on and plan properly for the future.