The Trump administration just proposed big changes to Obamacare

The proposals from CMS include several changes to enrollment periods and timelines for insurers in an attempt at "stabilizing the individual and small group health insurance markets," according to a press release.

The proposed changes would be the first administrative tweaks to the law, also known as Obamacare, under President Donald Trump's administration. They contain a combination of long-considered ideas and serious departures from the previous administration.

Perhaps the two most striking proposed changes are cutting in half the exchanges' 2018 open enrollment period and lowering minimum standards for care to qualify for the exchanges.

The CMS proposes an open enrollment period — during which people without health insurance through their employer or Medicaid/Medicare can sign up for coverage — from November 1 to December 15, 2017. Open enrollment periods have been three months, from November 1 to January 31.

Additionally, the rules would lower the "de minimis range used for determining the level of coverage," according to the release. Essentially, the ACA established minimum standards for coverage (here's a full breakdown from CMS) in order to be certified on the bronze, silver, and gold plan levels. The new rule would allow insurers to cover slightly fewer areas of health and still be at a certain metal level.

The CMS projects the rules would result in increased out-of-pocket costs for Americans in the short term but that lower premiums would offset this in the long run.

"The proposed change in [actuarial value] could reduce the value of coverage for consumers, which could lead to more consumers facing increases in out-of-pocket expenses, thus increasing their exposure to financial risks associated with high medical costs," the proposal says. "However, in the longer run, providing issuers with additional flexibility could help stabilize premiums, increase issuer participation and ultimately provide some offsetting benefit to consumers."

Patrick Conway, the acting CMS administrator, said: "This proposal will take steps to stabilize the marketplace, provide more flexibility to states and insurers, and give patients access to more coverage options. They will help protect Americans enrolled in the individual and small group health insurance markets while future reforms are being debated."

Here's a quick rundown of some of the other proposed changes:

Some of these changes were proposed by the Obama administration in August to address the imbalance in the exchanges.

The open-enrollment tweak may be the most significant departure from the Obama era, however. The CMS rules proposed in August tried to expand outreach and sign-ups for the open enrollment period, allocating more money toward advertising efforts. Trump's team pulled back from a good portion of a $5 million ad buy for the 2017 open enrollment period.

A shortened open enrollment period could also make it much more difficult to increase sign-ups or keep the number of people enrolled at the same level in 2018. The number of people who signed up during the open enrollment period fell in 2017 from the year before, mostly because of a significant deceleration in sign-ups after Trump took office.

The new proposed rules drew some criticism from health-policy experts. Larry Levitt, a senior vice president at the health-policy think tank Kaiser Family Foundation, tweeted that the rules "strike me as making things less consumer friendly and more insurer friendly."

The proposed changes are open for public comment until March 7, according to filings with the Federal Register.