Why am I getting billed from my ER visit ?

Tricare is an HMO it's not magic, it doesn't know who to pay if you don't give that information. It's only automatically covered on post and with network providers, and even that isn't unlimited.

You've learned a valuable lesson about health insurance and why people join the Reserves after active duty for health insurance. You're very lucky, this could have been a much more expensive lesson.

You need to get into the Tricare website to see what they do and don't cover, especially while traveling (like when you're on leave). You're required to contact Tricare and inform them when you seek emergency care off post within a day or two of being released. You need to do that now so that Tricare can cover your ER visit. Be aware that Tricare has caps on certain expenses and you might still be liable for some of the charges.

Did you tell them you were active duty when you were able to? I've had more experience using TRICARE with my daughter than myself off base - and the first time I go to any medical facility, I tell them I have TRICARE and give them the information they need so they can bill TRICARE. Things fall through the cracks though - when I had to take her to the ER that ended up with her being Life Flighted at 6 weeks old, I did get a bill for an Xray she had there. But I just ignored it since I had gotten the bill for the Life Flight but TRICARE covered it after I had looked into it. Then I got a "final notice" letter on the $100 bill. So I got ahold of the POC in the letter and they said "oh we didn't know you have TRICARE" and then they filed the claim with TRICARE after that.

So if I was you, I'd get a hold of billing at the hospital and see if they know that you have TRICARE. Then you can go online to whatever region you're in (TRICARE West or East) and contact them via contacts listed there if the hospital did send in claims.

TRICARE only covers claims that get filed. They don't know when someone gets medical care unless they get a claim.

Whether or not You end up paying all or part is going to depend somewhat on the Line-of-Duty investigation of Your accident. Did You try to get the ambulance to go to Womack? JAG should be one of your upcoming appointments.