Today's biggest news for older adults: Costco is entering the Medicare business. Reports say the warehouse chain will start offering Medicare plans as part of a major expansion, its first partnership aimed at senior care. For many members, it could become one more place to shop for coverage.

Medicare stays in the spotlight in other ways too. A new report suggests many people on Medicare feel sure they understand the program, but the data shows real gaps in that knowledge. And a Medicare pilot that discounts popular GLP-1 weight and diabetes drugs comes with a catch, since some very sick patients may not qualify.

There is also hard news from care facilities. A genetic testing lab faces a $315 million federal penalty over alleged Medicare and Medicaid fraud. In South Florida, a nursing home lost power during a heat wave, though staff avoided a worse outcome. And a family in the Lowcountry is suing after an Alzheimer's patient reportedly suffered nearly 1,000 ant bites.