Lets first go according to your numbers.
1. Time limit? probably not. Check your decree and IL state statutes if there is anything specified in either. Probably not. My state says reasonable....there's that magical word again.
2. Time limit and NOT responsible? Probably not. BUT on this point, I would argue (and
DH has won this argument), that if the insurance company hasn't paid because the claim wasn't submitted in a timely manner to them, then you shouldn't have to pay it either. (For Tri-Care, that's 1 year beyond Oct 1st after the year during which the date of service happened....like for August 1, 2004, we have until Oct 1, 2005 to submit.) Confusing -- but each insurance is unique and that's what I suggest you go by. Everything that happened BEFORE Dec 04 can still be filed against her insurance even if she is no longer employed. The kids were covered at the time of service.
3. Legally, Step-dad not required to provide insurance for the kids. I'm not 100% sure, but I think I read once where Soc said that a step-parents insurance is above and beyond everything and nope, they don't legally have to tell you about it. It's there for THEIR benefit and you can't take advantage. (not that I agree with that....) and I'd suggest you search his forum, but a lot of the older posts aren't there anymore.
From what I gather, you really have from Jan 1st to today to worry about.....19 days so far.
Lots of doctor's offices don't want to care (and they don't have to) about splitting bills 50/50 and basically keeping track of who paid what to whom. I too am a parent that wants to pay the doctor directly so I can understand where you're coming from. (6 kids -- tons of experience).
Here's what I think.....it's time to go back and renegotiate medical care coverage for your kids.
Why? The divorce decree gives her a simple out -- if you've posted the words correctly. She's not in violation at all...because it says she has to provide it as long as she can through her employer.
You need to find out if she got fired or quit to put the burden of having the insurance on the kids back on her like it was.
OR you need to pick them up under your insurance and then see if the courts will adjust your
child support because of this.
Not giving you the bills in a timely manner....yep, do your bestest to keep track of that.
Credit reporting or collections? Do a search under the Fair Debt Collections Act on this site. USE that to get your name off the bills at the doctor's offices because YOU didn't take the child into the office, period. There's a divorce here and fight back. There was a similar thread in another section (where I responded)....check that discussion out.
As for figuring out what the insurance actually paid -- getting back to my "slight" disagreement with the other person here.... On the statement that the doctor provides you, you should see what the insurance paid to the doctor and what their adjustment was. That actually suffices as a replacement for the EOB. If the insurance company pays the beneficiary directly, I'd refuse to reimburse the other parent until she provides the corresponding Explanation of Benefits to each date of service in question.
You might have to run or keep track of all this stuff in a separate spread sheet or something -- good luck in keeping yourself straight. Make sure HER bills and step-dad's bills are not in this mess.
That's probably part of the goal too -- to confuse you into paying more than your fair share.
Above all good luck and don't let her walk all over you!