How long do orthotics last?

Although this varies, our experience has shown us that orthotics last for many, many years, as in five to ten for most people.  With that being said, the top cover that over lies the actual plastic orthotic usually last from six months to five years or more for most people - depending on such variables as activity and time worn.  This is to say that a full time construction worker will wear their orthotics differently than an administrator who spends much of their day behind a desk.  With that being said, many people go for years without wearing down their top covers to any degree.  The good news is that it is relatively inexpensive to replace the top cover and "refurbish" your orthotics once a year to once every two years on average.  
As a general rule, depending on the severity of your instability, once you "break in" the orthotics and they have been assessed or adjusted by your doctor, the orthotics will not move or change much over time.  In some instances, if your instability is rather severe, you can - over time achieve a better structural position with your feet.  In this case, you may choose to be reassessed by your doctor in one to two years as, in some instances, a better degree of correction can be attained.  If this is the case, a new orthotic made in an even more corrected position can improve even further your alignment and thereby allowing you even better results.  With this being said, the great thing about this type of custom orthotic is its ability to be adjusted.  In many instances, a similar result can be achieved by a simple adjustment that your doctor can many times do in the office while you wait.  It is because of these factors that you should follow up with your doctor and have your orthotics and your structural position assessed periodically so that you can maximize your results and your functional capacity to the greatest degree possible.