Short term medical insurance isn’t health insurance, really, it’s accident insurance that functions like your car insurance. It also, generally (because I’m sure somewhere there’s an exception and someone will comment that this or that exists), isn’t offered by your typical health insurance companies. I.E. you can’t buy Aetna short term coverage. In some states this short term coverage is actually illegal to sell. Short term coverage is not skinny coverage, which functions exactly like your regular health insurance but has various limits, either dollar or service frequency limits.
People I’ve seen buy short term coverage are ex-pats who are returning to the US for several months at a time, or younger people who are healthy and don’t want to pay for COBRA, and live in a state where it’s not illegal to sell; which seems to be your situation.
There are absolutely pre-existing condition limitations. The ones I’m aware of also exclude any coverage for COVID treatment, and contain other general act of war, self-inflicted injury type exclusion language along with that 12/24 look back language. Again, this is not medical insurance. It is not intended to get you your annual physical or get you through a cancer diagnosis and associated treatment. It exists, really, to patch you up after a mountain biking accident or whatever while you wait for eligibility through your next employer.
I’ve seen some that have a contracted network, but there’s no incentive to use the in-network providers apart from the pre-negotiated rates. Coverage I’ve seen is priced with a pretty simple matrix of age and maximum, with different rate sheets for deductible and coinsurance percent. So a $1,000 deductible 90% coinsurance plan will have a rate sheet with ages and prices at each maximum of $250k, $500k, $1mm, etc limits.
A short term plan that I’ve also seen that’s less illegal and more like health coverage is a Medicare bridge plan. It’s at least somewhat common for an older working person to retire while they have a spouse who’s more than 36 months away from their own Medicare eligibility; so COBRA can’t cover the spouse for the entire time between the breadwinner retiring and the spouses own eligibility. Medicare bridge plans tend to have a provider network and basically mirror Medicare coverage but still run more like indemnity coverage.
Anyway, yes assuming you live in a state where it’s legal to sell short term coverage, your pre-existing condition is excluded from coverage. If your plan has a provider network (again, a lot of these options don’t) you can use that network for pre-negotiated rates. A common network for these kinds of plans that has a network is called Multiplan, generally referred to as MPN (other big carriers and employer health plans use multiplan too).
If pre-existing conditions are a concern for you there exists now ACA conforming coverage available to you on a potentially subsidized basis in all 50 states. Short term coverage might not be the route to take. If you have a pre-existing condition you can definitely buy coverage that will include it, this was not always the case.