The Colorado concealed handgun permit is valid for 5 years. Every 5 years it must be renewed. The renewal process is a lot like the original application process. You go back down to the county sheriff office and fill out some paperwork, potentially take a new picture, and wait for them to process the renewal. The renewal of your ccw permit can cost as much as $50 but per Colorado statute the county cannot charge more than $50.
At the point of each renewal you must show ongoing proficiency with a firearm, which is legal jargon for you have to have a valid class certificate or other paperwork that satisfies the training requirement. All training is valid for exactly 10 years from the date you received the training. This intuitively implies that on your first renewal, after having your ccw permit in Colorado for 5 years, the same paperwork or class completion certificate will still be valid and will suffice for the renewal. That is correct but there are a couple of other things worth clarifying. First, you must have a class certificate with an original signature both at the time of application and renewal. That means it is important that you show the county employee the original but ask them to make/take a copy and leave you with the original.
Also, you can renew as early as 120 days prior to your permit expiration date. That suggests that if you are really ahead of the schedule you could utilize the same class certificate for your initial application and two renewals.
Although I have received mixed feedback from counties when I've asked the question; experience suggests that many counties will not notify you in any way when you are due for renewal so you had best be watching the date.