According to gerontologist Robert Atchley's phases of retirement, in what phase of the retirement experience do retirees learn to deal with life after retirement in a reasonable and comfortable fashion?

the stability phase

Explanation:

Although retirement does not have an end, people who properly prepare for retirement enjoy this stage of retirement. In this phase according to Robert Atchley, this is not the planning or thinking stage anymore, but a stage where the retirees are actually living it. Achieving success in retirement becomes a wonderful period because in this stage, retirees learn to deal with post-retirement life in a more comfortable and fulfilling fashion.