It’s a popular proposal, especially among Republicans: Let people savemoney by buying insurance coverage from another state, wherepolicies might be cheaper. But it’s not a good idea, according toKaiser Health News. The reasoning was laid out in awebcast.

Presumptive Republican presidential candidate Donald Trumpsupports the selling of insurance across state lines, as does TedCruz, but the idea isn’t new. In fact, according to Kaiser, theidea has been kicking around for more than 10 years.

And three states already allow it: Georgia, Maine and Wyoming.In fact, so does the Affordable Care Act, as long as all statesinvolved agree to it.

However, for several reasons, “not a single insurance companyhas offered” to sell a product approved in one state to people inanother, the report said.

One biggie is the whole network idea. A person who lives inFlorida, for example, and wants to buy a plan sold in North Dakota,is going to have a problem when it comes to finding doctors andhospitals in the network in his state. After all, the network wasconstructed for North Dakota residents and therefore Floridadoctors and hospitals will be in shortsupply.

Then there’s the idea that people could save money by buying aplan from another state with lesser requirements for expensivebenefits — meaning the insurance company is less likely tooffer autism coverage, say, or fertility treatments, oracupuncture.

After all, someone without an autistic family member or thosewho have no interest in fertility treatments and hate the thoughtof acupuncture needles could probably save a few bucksthere.

But again, that doesn’t work as well as one might expect, andone reason is the ACA, which imposed a more uniform standard ofofferings required of insurers. So there’s less variation fromstate to state than one might otherwise expect. While Republicansmight be assuming that the ACA will be repealed, thus renderingthose standards moot, if repeal doesn’t happen, those uniformstandards will stay in place.

And if the kind of coverage in questions is something that a lotof people actually might need — diabetes, say, or cancer — and onlyhealthy people buy the policies from states that don’t require suchcoverage to be offered so that they can save money, that means thatall the people who actually need treatment for diabetes or cancerwill have to buy in their home states, thus driving up the price ofcoverage for everyone in that state.

Last but not least, there’s the fact that if you have a problemwith that South Dakota policy, good luck getting any help from yourFlorida insurance commissioner; he won’t be able to help you with apolicy sold in another state.