Are ACA-compliant plans sold outside the exchanges eligible for subsidies eventually?

My understanding has long been that one has to buy their plan on the appropriate government exchange (healthcare.gov for most states, or the state exchange for states that set up their own state exchange) in order to qualify for the premium subsidy and the out-of-pocket costs subsidy.

(By way of background, I'm in Minnesota, which has a state ACA health insurance exchange called MNSURE at MNSURE.org (don't ask me why its not MNSURE.gov) )

Now I'm being led to believe by a HealthPartners salesperson that all ACA-compliant plans, whether or not they are available on the appropriate exchange, is eligible for the subsidy.

He says (if I understood correctly):

(a) That those who buy their plan on the government exchange get immediate relief -- their monthly premiums are reduced by the subsidy. (I know that to be a fact because early last year I bought such a plan on MNSURE, and my monthly premiums are reduced by the subsidy)

(b) That those who buy an ACA compliant plan outside of the exchange also are eligible for the subsidy, but must wait until they file their tax return in order to get the subsidy (e.g. as a result of filing 2015 taxes in say March 2016, I will get whatever subsidy I'm entitled to for 2015 in the form of a refund (or reduction in taxes owed)). This statement I doubt.

(c) All HealthPartners individual plans -- not just the ones available on the government exchange (in my case, Minnesota, the MNSure state exchange) -- are ACA compliant. That agrees with a HealthPartners brochure that says:

"Key plans meet all of the requirements of the Affordable Care Act. In fact, all HealthPartners individual plans meet the standards so you don’t have to worry!"

So my Truth-o-meter says (a) and (c) are true, but (b) is very questionable -- nothing I've seen on HealthPartners literature (or anywhere else) says anything other than that only plans bought through the government exchange are eligible for tax credits and subsidies. Also he said he hasn't seen the 2015 tax forms yet (sounds like he's giving himself some wiggle-room).

(I'd call HealthPartners again, demanding something in writing or to be shown something on their web page that states this, but they aren't open until Monday for questions like these, which is also the deadline for changing plans that will take effect January 1).

I would like to look at HealthPartner plans other than those on MNSURE, but am afraid what I'm being told (that I'll get my subsidy after filing taxes) isn't true...

Does anyone have some perspective on this issue? Not just in Minnesota but in general -- are ACA compliant plans not sold on the appropriate government exchange eligible for the subsidies after filing taxes?

If not, why not?

Thanks for any info.