"Financial adviser?" No. That is an ambiguous term with no standard behind it.
A fee-only certified financial planner? (CFP) Yes. I did a financial plan with one about 8 years ago, as we were expecting our first child. It cost $1,200, if I recall, but I could come back for a "refresh" for $400 within 2 years.
I didn't end up consulting with one when I retired (also at 48!) but I had spent a lot of time myself planning for it, so I was fairly confident.
I think the role of a planner is twofold: yes, to inform you of things you don't know about. But if you are Mustachian, there likely isn't much new there. The other thing, which might be what you are looking for, is guidance to help you stick with your plan. Maybe That's a phone call in week 2 of the invasion of Ukraine, with tech stocks down, and your sell finger is getting itchy. Maybe That's a consultation if your husband wants to take up an expensive hobby or start a side business when he retires. Those kind of things are more a sounding board: a third party who fully knows your situation, but doesn't have any emotion about your situation. Both roles can be worth the money--it's cheaper than making a mistake, when your stache is big enough to be FI.
Medicare I know nothing about. Of course, the ACA has guides that can help you choose a plan. Will be good to know if there is something similar.