If you're planning to take a flight within the United States in 2018, you may need to get a passport. Normally, a passport is only required if you are traveling in and out of the country. Thanks to new TSA regulations that will be implemented in January 2018, residents of nine states who are boarding a domestic flight will no longer be able to use their state-issued driver's license as identification.

Passports required to fly from state to state

According to Travel and Leisure, adults who have a drivers license in one of the nine states below will have to pony up $110 for a Passport ($30 for the card).

The TSA will require a passport to travel domestically starting January 22, 2018, for residents of Kentucky, Maine, Minnesota, Missouri, Montana, Oklahoma, Pennsylvania, South Carolina, or Washington.

For example — if you live in Missouri and are booking a trip to Disney World anytime after January 22, it's time apply for a passport. Your license will no longer be valid as identification.

Is there an alternative to using a U.S. passport?

If you have a permanent resident (green) card or a valid U.S. military ID, either one will be accepted in place of your driver's license.

However, for those who don't, a passport will be required in order to pass the TSA checkpoint prior to boarding a domestic flight.

Why won't drivers licenses be accepted at the airport check in?

The new TSA rule won't begin until January 22, 2018, but the signs are already going up at the airports in Kentucky, Maine, Minnesota, Missouri, Montana, Oklahoma, Pennsylvania, South Carolina, or Washington.

Apparently, the driver's license issued in the states listed above fail to meet the federal government's Security standards.

Travel and Leisure state that the changes are related to the Real ID Act of 2005.The states' driver's licenses and state-issued identification cards in the nine states noted do not meet the Act's "minimum standards."

In short, the federal government's standards require the verification of the applicant's identity when they apply for a license or ID.

In addition, the cards must be produced with anti-counterfeit technology and background checks must be performed on the people who issue the driver's licenses.

Driver's licenses in the nine states currently do not meet the standards. That's why a passport, military ID, or resident card will be required starting in January 2018.

More states may be affected

Right now, the TSA only plans to implement the ID requirements in the nine states listed above. However, by 2020, travelers nationwide will have to have Real ID compliant identification or they won't be able to board their flight.