First, let me say that I really appreciate all of the replies. It's hard not to feel isolated in a situation like this, so having some feedback is really valuable to me and makes me feel a bit more calm about the entire issue.
For the sake of readability, I'll write the questions I have now here at the top, with my responses below that.
1) How can I determine if falsifying the documents rises to the level of a criminal act, vs an unethical one? If I don't see the phrase "under penalty of perjury", it seems unlikely that providing false documentation would constitute fraud, particularly since these are funds I've paid in, as opposed to funds belonging to another person or entity.
2) How can I find out who actually reviews this information, without asking my HR team directly? For the sake of clarity, I feel safe identifying Fidelity as the site where my 401k information is administered.
@Lou S. - I've been following the legal developments around it, however it looks like most of the successful cases are more aligned with payouts to a state vs payouts to individuals - the intention being that the state will bear the burden of programs designed to deal with the issue. Also, I imagine there's a concern about giving a bunch of addicts a lump sum in a settlement, which I have to say is probably justified.
@ratherbereading - This point actually interests me quite a bit, because I wonder how dangerous it would be to lie about it. If it's not legally actionable, it seems like attempting to lie about the costs (assuming I could do so convincingly) would be a potential workaround. Even if I got caught doing it, worst case I could come clean and explain that the stigma of addiction was my motivation in attempting to falsify the data. How could I ascertain whether or not lying about this rises to the level of criminal conduct vs unethical conduct? If the documentation doesn't contain the phrase "under penalty of perjury", I wonder how dangerous it is. To be clear, I'm not directly asking whether or not it's illegal (as giving/taking legal advice on the internet is unwise), I'm asking how I could try to determine the legality of the situation, or what resources would help me determine that, short of legal council.
@llkmrw - Great questions. 1) I'm not sure. How could I investigate this, aside from directly asking my HR team? 2) I'm not sure that's possible - from the sound of things, they're looking for an itemized list of costs, so I'm not sure fudging codes will help - in fact, the provider may be specifically forbidden from doing so. As far as approaching my HR team, even with documentation of who I spoke with, proving a leak is nearly impossible. It may be wrong of me to feel this way, but I just don't trust anyone to keep this classified - this is my livelihood, and with a wife and child to support, I feel it's too dangerous to rely on anyone else to ensure I'm not burned here.
@Belgarath - This is the core of my concern. While I'd like to believe the best about people, when it comes to my career and the future of my wife and child, I simply can't trust the discretion of other people. I've experienced gossipy HR people in the past, and it's just too dangerous. Side note: I, too, am a David Eddings fan! If only The Will and The Word could help me here.
@rr_sphr - I have a great deal of vacation time built up and intend to leverage this instead of FMLA, obviating the need to provide documentation for that purpose.
Again, I'd like to thank everyone for their replies and words of encouragement. While I know we're all strangers on the internet, it's nice to feel like someone, somewhere appreciates my plight.