With insurers leaving markets, some Obamacare users "really nervous"

Open enrollment for Obamacare, or the Affordable Care Act, begins today. Problems with the law mean consumers could face significant rate hikes in some parts of the country. There will also be fewer health plans to choose from.

• Why Obamacare premiums are rising — and what you can do

Starting today, the administration will make a major enrollment push — but that may be a tough sell in states like Tennessee, which has seen premiums spike more than 50 percent, reports CBS News correspondent Margaret Brennan.

Watch the full piece today around 7:30 a.m. ET on “CBS This Morning.”