With this case, its level of complication is only surpassed by it’s level of boringness. I’ve read it multiple times, and have basically determined that it’s just a prime example of how when government writes a law, they only make things overcomplicated and inefficient.
Basically, the gyst is this. Medicare and Medicaid pay hospitals for treating patients. The amount they pay, is a set amount for a set procedure. So if you have to get your taint amputated because you have ass cancer, they might pay $10,000, no matter where you get that shit done.
That being said, there are hospitals, knows as Disproportionate Share Hospitals (DSH). These hospitals exist to help underprivileged Americans get care they might not otherwise be able to afford to get at other care facilities. As such, these hospitals are broke AF, and need money to help cover these extra expenses. DSHs get higher payments, since their patients are poor, and often in worse health, needing more treatment, as a result of their financial situation.

The Health and Human Services agency, has an algorithm to calculate how much to pay these DSHs., which basically looks at their Social Security Insurance (SSI) benefits, time spent in the hospital, and whether Medicare and/or Medicaid pay for it.
They have two separate algorithms for Medicare and Medicaid, to try to catch everyone using one benefit or the other, but then special rules to make sure if a person uses Medicare and Medicaid, they aren’t counted twice.
This is where it gets laughably complicated. The issue is regarding the phrases “entitled to” and “eligible for.” In the English language, they certainly mean two different things. The first means, it’s yours unless a reason is presented it should not be. The latter means it could be yours, if reasons are presented it should be.
But, HHS, apparently unaware of the English language, treated them as essentially the same. Both phrases represented patients whose bills were paid my either Medicare or Medicaid. But then, an appellate court, looking at the phrase “eligible for” came in and was like, “We don’t give a fuck if Medicare or Medicaid paid their bills, if they’re eligible for either Medicare or Medicaid, then they’re to be counted.” This new definition, broadened the “eligible for” phrase, which now makes the two phrases in question mean something different.
So then, HHS was like, “Well fuck you, appellate court. We think they’re the same. So if you’re going to redefine “eligible for” while just redefine “entitled to” to mean the same thing, using your new and broader definition.

So now, SCOTUS must decide, if HHS overstepped its bounds, broadening these definitions of the statute (as opposed to congress rewriting the law, I’m guessing), which would result in billions more taxpayer dollars finding their way to DHS locations around the country.
In a 5:4 decision authored by Justice Kagan, and joined by Justices Thomas, Breyer, Sotomayor, and Barrett, SCOTUS ruled HHS fucking nailed it. That it doesn’t matter if those agencies paid for the care, if the people were covered by these programs, they count, and HHS is well within their scope of authority to interpret the rule that way. As such, these people can be included in the algorithm, whether Medicare paid for their shit or not.

If I understand this right, and fuck me if I don’t, because this shit is confusing. Since there’s only so much money to be paid out, by expanding the number of people covered in the algorithm, it means the available money is divided up and doled out to more hospitals, thus reducing the amount DSHs will get over regular hospitals.
Justice Kavanaugh wrote the dissent, with Roberts, Alito, and Gorsuch joining him. They looked at the statute itself and felt that if Medicare doesn’t pay for the care they received by statute, the patient and DHS aren’t “entitled to” get Medicare to pay for it by adding them into their algorithm anyway.
Hear oral arguments and read about the case at Oyez here, and SCOTUS Blog here.