Aetna offers many types of work at home positions; however, you may have to start out working in the office. You will want to search for jobs that are "Potential Telework Positions," which is an option in their search form. As of this writing (2016), their website states that 43% of their employees telecommute.
Be aware that location often matters with jobs for Aetna. This is because medical jobs may require licensing in the state where the job is located. Not all jobs are medical, of course. There are technology and customer service positions as well.
Job titles may include Medical Director, Implementation Manager, RN Case Manager, DevOps Engineer, Network Account Manager and more. Benefits may be available to full time employees.