In Maryland and all states military retirement is considered property subject to distribution.
The court will, if she requests, assign her a "marital share" of any military retirement.
Once he retires she and your son will have to submit the appropriate documentation to the Defense Finance & Accounting Service. They can they arrange direct payment of her share to her.
The marital share is calculated on the number of years married and how many of those years overlap with military service.
Here is some more general information
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Your questions asks whether a military pension payout is "alimony?" Generally, "no" it is not considered alimony; instead it is considered an asset that has accumulated retrospectively, whereas alimony is a prospective sharing of income after divorce.
Still, if the Court knew the amount of her share of the military pension the Judge will consider that amount when s/he decides if there will be alimony and if so how much that alimony will be. Specifically, in addition to many other factors, Maryland Law requires the Judge to consider all of the property and resources of each spouse at the time of the alimony award.
The other attorney can get the information s/he seeks from the military but you are correct that your son's retirement amount will depend on his rank and years of service at retirement. However, unlike civilian retirements he will be entitled to receive his retirement distributions as soon as he retires and he will not have to wait until he is 59 1/2. Another important issue to consider for both sides is your son's ability to claim a portion of his military retirement as disability which will then be excluded from distribution to his former spouse (this is a concern for the military spouse, not the service member).
The Rule is that the wife, if she was married to the service member for 10 years or longer during his service, shall get 1/2 of the marital share of his eligible (not VA disability) military retirement when he retires provided that all other rules and appropriate forms are followed and filed. Most of these actions are the concern and burden of the wife and her attorney.
While not considered alimony, it can be divided as part of the marital property. If he has not already done so, he should contact a family law attorney in Maryland with experience in military divorces. I used to work with Kevin L. Beard in Catonsville, and he is very experienced in this area. Would be worth call if he doesn't have counsel yet.
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