MIAMI (AP) — Dear seniors, your Medicare benefits aren't changing under the Affordable Care Act. That's the message federal health officials are trying to get out to elderly consumers confused by overlapping enrollment periods for Medicare and so-called "Obamacare." Medicare beneficiaries don't have to do anything differently and will continue to go to Medicare.gov to sign up for plans. But advocates say many have been confused by a massive media blitz directing consumers to new online insurance exchanges set up as part of the federal health law. Many of the same insurance companies are offering coverage for Medicare and the exchanges.