There is a fair amount out there on the web about spousal support and retirement. My colleagues discuss the leading cases quite intelligently. I recommend that you read what they have to say. I am going to distill down the current wisdom based on the cases to a few numbered points. But remember, each case is different. Before you plan to retire, it pays to have a consultation with a family law lawyer.
1. The Base Starting Point: It's really important to examine what your final order or Separation Agreement says about retirement. If it says nothing, then you might be in for some rather unpleasant surprises. If you have not yet finalized your 'first go around' court order or Separation Agreement, then you would do well to squarely address in that order or Agreement just what effect "retirement" will have on the order.
2. Retirement Alone: The mere fact of retirement alone is not sufficient to automatically trigger a spousal support reduction.
3. Voluntary vs. Forced Retirement: Being seen to retire voluntarily (as opposed to being forced out) will most likely not auger well for a spousal support reduction. You can't just retire because you want to (believe it or not!). If it looks as if you are retiring to just get out of paying spousal support, then you will not receive a very warm reception from the court.
4. Health Reasons: If you need to retire because of failing health, you should be able to fully and contemporaneously document with a licensed health care professional your mounting health issues: Symptoms, Diagnosis, Prognosis, Effect on ability to perform duties of your own occupation, Effect on ability to perform duties of another position for which you might be qualified.
5. Re-partnering: If you have re-partnered with a well off person, that will be worse for you than had you re-partnered with a pauper.
6. Timing: Retirement must be a certainty when you make your Application; it cannot be speculative. It is good to give the former spouse as much advance notice as possible. (It is even better to include the minimum notice period in your first court order or Separation Agreement.) Be considerate of the former spouse's financial circumstances and potential impact on the support recipient. It's not just a matter of being "civil" and "polite"; it is one of the factors that courts will look at.
7. Double Dipping: The famous Boston case has some musings about not re-using for spousal support that part of your pension that was already shared in the property settlement or order. But Boston and other cases make it very clear that where there is "need" and/or compensatory factors to the original spousal support order that have not yet been sufficiently compensated for, then indeed "double dipping" will be allowed. Boston does not create an absolute prohibition against accessing the already equalized portion of your pension to provide spousal support later in life.
8. Ability to Pay: The court is mandated statutorily to examine all of your circumstances and "means". Therefore, the court can consider all income sources, all capital, and even your new partner's income (although perhaps not always on a dollar for dollar basis). If you have an ongoing ability to pay, notwithstanding your retirement you may be required to continue to pay spousal support at the same level, or sometimes even at a higher level. Sometimes, spousal support is reduced.
9. Reminder - the Facts!: Remember that the facts of your own case can have a significant effect on how one prepares your case and ultimately advances your case. What I have related here are only general principles. There may be exceptions. There are certainly nuances. Proper preparation and strategizing can go a long way to secure a decent outcome.