Using the Fepblue for reference (it's easy as an exemplar with three clear categories, but plans and costs vary of course):
Blue Cross and Blue Shield's Federal Employee Plan
Basic is the healthy plan and for network coverage
Standard is the plan for more ill members and all provider network (non-network allowed)
Focus is the HDHP plan
All of them have a $10k catastrophic coverage ceiling (meaning that you won't pay more than $10k any plan year, which gives you a worst case scenario).
Speaking with a Fed and actuarial hat on given how FEHB (government insurance for employee plans are public information) works. If you're healthy and it's just you, you can do the HDHP plan with assuming bigger risk. If you end up spending more than $3-4k within a five year period, then no. Looking at our FEHB payout data, using the HDHP works until that one bad year, and that bad year is a really bad year for a federal employee. I generally recommend that families that have one child or more get at least the Basic plan, because the out of the money expense for one serious childhood illness or injury is high enough that it's worth the cost and switch over to the Standard if there is a high cost event in the near future (OB-GYN for delivery or a new chronic illness). For someone who is solo, it's debatable.
(Actuarial hat off)
I don't think though that the idea of having an HDHP plan would recoup enough from investing to offset the obvious risk profile for a high expense medical event (and you all work in this industry to know how obfuscated the "costs", "charges", and "prices" that negotiation is practically a lost cause).
Personally, I have the Standard plan for fitting the problem of having a chronic disease (asthma) that has four meds and one of them being biological that offset any real expenses that would have come with the higher plan and traveling enough that I don't want to worry about going to an out-of-network provider (I ended up admitted to SF General once who ISN'T a Blue Cross provider, and Blue Cross had to eat the differential costs, otherwise, I would have been stuck with a $12k bill for an out-of-network provider). I also don't think that even if I were given the HSA for free with standard coverage, I would bother investing it considering that it's actually a bigger utility to have that money there to spend on some crazy medical incident (fall down Mt. Matterhorn in Switzerland and needing medical evacuation like my boss did).
