I don't write a whole lot about Medicare, since just about all U.S. citizens over 65 are covered by it and therefore don't enroll via the ACA exchanges anyway. However, it does come up on this site from time to time, and a good 55 million or so are enrolled in the program, so this little story might be of some relevance:

I hereby admit that a) I don't know much about Medicare (remember, my major focus is on the ACA exchanges, Medicaid expansion, the individual/small group market and so forth) and b) I'm swamped at the moment so don't have time to do a real analysis/write-up on today's announcement, but it appears to be a Pretty Big Deal, so I'll just present the press release/statement for the moment:

U.S. Department of Health & Human Services • Monday, July 25, 2016 • News Release • 202-690-6343

Important Next Step towards a Better, Smarter, Healthier Medicare:
New Payment Models and Rewards for Better Care at Lower Cost

Today, the Department of Health & Human Services proposed new models that continue the Administration’s progress to shift Medicare payments from quantity to quality by creating strong incentives for hospitals to deliver better care to patients at a lower cost. These models would reward hospitals that work together with physicians and other providers to avoid complications, prevent hospital readmissions, and speed recovery.

I very rarely write much about Medicare here, partly because I just don't have time to cover every aspect of the healthcare system, partly because Medicare is only impacted by the ACA indirectly for the most part. However, there's been two recent developments which are worth noting:

First, that "indirect impact" I just mentioned has resulted in the Medicare Hospital Insurance Trust Fund, previously expected to run out of money just 2 years from now, now being expected to be solvent through 2030 thanks to the ACA bending the cost curve:

The slowing growth of healthcare costs has extended Medicare's projected lifespan 13 years beyond projections made in 2009, the last report issued before the passage of the Patient Protection and Affordable Care Act.

The Medicare Hospital Insurance Trust Fund will have "sufficient funds to cover its obligations until 2030," the Medicare Board of Trustees said Wednesday in its annual financial review of the $613 billion program.