You might think there's nothing new to know about Obamacare at this point. Most of what you've already learned about the Affordable Care Act is still the same -- but not everything. Here are a few things you need to know about Obamacare as 2015 rapidly approaches.

Healthcaregov Nov

Source: Healthcare.gov

1. Open enrollment is cranking up again
Last year, open enrollment lasted from Oct. 1 through March 31, with a two-week extension for people who had problems enrolling. There is a shorter period for 2015, though. Open enrollment starts on Nov. 15 and ends on Feb. 15. Note, however, that you need to enroll by Dec. 15 for coverage to be effective on Jan. 1, 2015.

If you enrolled in an insurance plan for 2014, you should receive a notice about how to renew your current plan. Many individuals will able to automatically renew their plans. If you want to change your plan, though, you'll need to do so during the open enrollment period.

2. Where you enroll could have changed
For most Americans, where you sign up for health insurance with Obamacare won't change. However, that's not the case for residents of some states.

If you live in Idaho, you'll need to go to your new state health insurance marketplace at YourHealthIdaho.org. This website should be used instead of the federal website that serviced Idaho during the last open enrollment period.

On the other hand, if you're from Nevada or Oregon, your state health insurance marketplaces won't be available this time around. Instead, you'll need to visit the federal Healthcare.gov website to enroll.

3. Penalties are much higher
If you don't obtain health insurance coverage, be prepared to pay steeper penalties. The "shared responsibility payment" for not having coverage in 2014 was the higher of 1% of annual household income or $95 per adult ($47.50 per child under age 18). The maximum penalty for a family using the latter method was $285.

For 2015, the penalties jump to the higher of 2% of annual household income or $325 per adult ($162.50 per child under age 18). The family maximum with the latter method increases to $975. 

4. If you like your plan, you might be able to keep it
There was a lot of hoopla in late 2013 about individuals whose insurance was canceled because the plans didn't meet the minimum requirements established by Obamacare. President Obama and other politicians had promised that "if you like your plan, you can keep your plan." As a result of the backlash when that promise turned out to be overly optimistic, insurance companies were allowed to continue offering these plans. Not all of the insurers reinstated the previously canceled policies, but some did.

If you still like your grandfathered plan, you might be able to keep it -- but you might not. The "keep your plan" change was extended one more year, but that doesn't necessarily mean that your plan will continue to be offered. Your health insurance company should contact you about the status of your plan, but you'll definitely want to get in touch with the company if they haven't. 

5. A lot could change
Next year could bring significant changes for Obamacare. For example, the new Congress could push to repeal the medical device tax included with health reform. This idea has bipartisan support and could conceivably gain approval from President Obama also. 

An even bigger change could come through the judicial branch. The Supreme Court decided recently to consider a challenge to how federal subsidies are given to residents of states that don't operate their own marketplaces. This case holds the potential to cripple Obamacare in 36 states.

Pay more, pay less -- but pay attention
Your pocketbook can be affected significantly by Obamacare in 2015. On the negative side, there are the penalties for not having coverage and higher insurance premiums for some. However, some Americans will also benefit from the subsidies for purchasing insurance and Medicaid expansion.

Investors could also see fortunes made or lost. For example, this year has only been so-so for shares of St. Jude Medical (NYSE:STJ) -- a repeal of the medical device tax could help this stock kick into higher gear. 

On the other hand, a decision by the U.S. Supreme Court to disallow federal subsidies in states that opted out of creating their own health insurance marketplaces would likely hurt hospital stocks. Take for instance HCA Holdings (NYSE:HCA); it operates in 20 states -- 13 of which don't operate their own healthcare marketplace. An adverse decision by the Supreme Court could put a big dent in HCA's share price.

Regardless of how you're affected financially by Obamacare, you definitely want to pay attention to what happens in 2015. It could be a wild ride.

Keith Speights has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.