Here’s a good discussion of non-ACA short term plans and alternatives.
https://www.bogleheads.org/forum/viewtopic.php?f=2&t=232507
The main benefits are being 1/3 the typical cost of an unsubsidized ACA plan, and giving a good network of doctors. The downsides are preexisting exclusions or other health-related disqualifications (i.e. They don’t have to take you), possible limitations on certain medical issues like maternity or mental health and drug coverage, and of course a possible tax penalty (YMMV getting out of this). BruDude, an insurance broker who used to be on FWF and was quite helpful, had some good comments half way down:
Petersen and National General have short-term plans with national PPO networks that can be extended for up to 12 months. You have to buy a 3-month policy and then it can be renewed up to 3 times. If you are diagnosed with a pre-ex condition during one of those periods, it will be covered in the following period. They do not cover pre-ex from before the policy was purchased though, don’t cover maternity/mental health/preventative care, and they aren’t compliant for tax purposes.
If the lowest priced bronze plan on HC.gov is more than 8.16% of your household income, you would be exempt from the penalty since it would be considered unaffordable.
I would stay away from any ministry sharing plans and US Health Group.
The Petersen and National General policies allow for guaranteed renewal and pre-ex conditions developed in a prior coverage period are covered, but pre-ex conditions from before the first policy were bought are not covered. Ex: Buy policy that starts January 1, have heart attack January 30, renew policy on April 1, heart attack/complications still covered. Pivot/Companion Life also has one of these type of policies available. Options vary depending on what state you’re in.