My situation might be a little different from yours, but here is what we do:
Dad was career AF (22y). Because of his length of service and never having paid in to Social Security (back when that was optional), neither he nor Mom have ever been eligible for SSI or Medicare. We always went to a local military hospital when I was a kid. Mom always went too, until the military started forcing her into their TRICARE HMO. There was a hitch when she turned 65--they required proof from Social Security that she was NOT eligible for Part A and B Medicare at no cost (or something like that. My understanding is that everyone over a certain age can buy Medicare, but since they did not pay into SSI, it would cost more). When Mom applied for SSI they sent her a denial letter and Tricare/DEERS/Whatever were fine with that as evidence.
Our experience with this has mostly been positive. It is $230 a year (that's correct--1 year) for the HMO plan. Phys co-pays are either $7 or $12. Prescriptions are free if you have access to a miltary pharmacy and they are on the formulary, $3 for 30 days if you use a local pharmacy, $3 for 90 days if you use the mail order pharmacy. More for brand-name drugs, but we have not used those yet, so I could not tell you how much. I can tell you that mom was hospitalized in an emergency (at a non-participating hospital, even) and once approved by Tricare, 14 days cost her $30.00.
The hitch for us has been that we DO live within 30 miles of a military hospital and a couple of times when we have needed a referral to a specialist, we have been referred there rather than out in to the community. This is mostly just a pain as in a military facility, any personnel in uniform are automatically rushed to the front of the line, appt or not, so it can take a good chunk out of your day. But like I said, it's only happened a couple of times.
The other hitch is that like any HMO, medical practices get to decide if they will even TAKE Tricare. So you may not be able to stay with your regular physician.
If you have a dependant ID, probably the easiest thing to do is find out where the Tricare liaison office is at your nearest Military medical facility. You may also check with DEERS when you are there. between the two of them, they should get you pointed in the right direction.
Just whatever you do, don't miss a payment for Tricare. If you terminate the policy, it's an automatic YEAR before you can re-enroll.
If you are eligible, chances are your husband is too, but I don't know all the ins and outs. Check with DEERS to be sure.