If the pre-motor and HEPA filters are well-maintained, they don’t need to be replaced. However, like any vacuum, you may need to buy replacement filters if they get damaged.
Note that there’s an inconsistency on Shark’s website of how often you should replace the HEPA filter. In the vacuum’s manual, it suggests cleaning it once a year, but in the HEPA filter’s product description on their website, it suggests replacing it every six months. These results reflect the manual, so you should clean it once a year.