Federal law supersedes state law. Part of the reason LEOSA was passed was to trump those states that restricted officers form other states form carrying.
If you have a police retired ID that indicates "Retired in Good Standing," and a LEOSA card indicating you passed yearly qualification, you are good for all 50 states period.
In MD, MSP will give officers retired in good standing, who make a timely application after retirement a free, non-restricted handgun permit. The only real benefits are you don't have to qualify and it is free, but it is only good in MD.
If you have LEOSA certification, you don't need a MD handgun permit.
If your agency won't do LEOSA certifications, (mine would not for fear of lawsuits....idiots) you can go to the Training Commission in Sykesville and get what you need of $50. You have to make a reservation, and they do the class once a month.
PG Community College also does it, but it is pricey, $125 if you don't live in-county.
My friend is a retired LEO moving to FL in Sept so he won't be able to qualify at his old agency. What does he do? As of right now he never got his LEOSA only a MD CCW which he can't use traveling theu the Carolinas.