A new phone dialing protocol takes effect this weekend.

As of Sunday, 10-digit dialing will be required in the 219 and 574 area codes.

That means the area code will be needed for all calls, even local ones. Long-distance calls still require a one before the phone number (ex, 1-xxx-xxx-xxxx.) 

Rates and coverage areas are not affected. Also, three-digit numbers like 911 and 211 do not change. Be sure to check your programmed phone settings to make certain area codes are included.