Tuesday marks the first day of open enrollment for people with insurance under the Affordable Care Act.

And while President Barack Obama has encouraged consumers to shop around, some people in Colorado have dwindling choices when it comes to their health care.

In fact, for 14 of Colorado’s 64 counties, those that need insurance only have one carrier to choose from: Anthem Blue Cross/Blue Shield. In 2014, every county had at least three carriers – and some had up to eight.

Even though there may be only one option, experts say to choose wisely when picking a plan.

A common mistake? Paying too much attention to the monthly premiums.

What might actually seem like a cheaper option per month could be more expensive in the long term.

That’s because a cheaper plan may not cover your specific doctor, your nearest hospital or all of your prescriptions.

If you have insurance under the exchange, your rate for the same plan you currently have could be higher next year.

That’s why it’s worth it to evaluate other plans even if you’re satisfied with your current coverage.

Experts say good, old-fashioned note-taking works best when comparing plans. Look at each one carefully and write down the pros and cons.

Also be mindful of your deadlines.

People with coverage under the Health Insurance Marketplace have until Dec. 15 to enroll or change their plan if they want to start coverage on Jan. 1.

Because of dwindling health insurance choices, the Colorado Division of Insurance says about 92,000 people will need to switch plans.

The Associated Press contributed to this report.