Great question and future planning.
Normally and depending on the field, there is usually always what is called a "cost of living raise". Each year, there are raises to things such as taxes and expenses so most places take this into consideration when doing their fiscal paperwork in order to be able to provide staff with this cost of living raise. In most places, this is either preset by the company or determined by hire date as a yearly raise date. There are other places that have incentives throughout the year that make them able to provide pay raises for employees throughout the year. The best advice here would be to check with the place you are looking to seek employment from and find out how they do their benefits package and what type of raise is included in that.