Classification is a sport-based system of levelling the competition playing field for athletes with a physical disability.The classification system has been designed to minimize the impact of disability on the outcome of competition so that athletes who succeed in competition do so on the basis of their sporting ability not on the level of their disability. Like boxing or weightlifting, where athletes are categorized by weight classes, athletes with disabilities are grouped into classifications (referred to as "sport classes") defined by the degree of function presented by their disability. Athletes undergo an evaluation that first determines their eligibility to compete and then groups them into a competitive sport class. An evaluation consists of standardized tests which are assessed by medical and technical experts on a classification panel.

Para-Nordic skiing (Cross-Country and Biathlon) is divided into three main categories each with several sport classes. In competition each category is run as a separate medal event.

• Standing  LW 2-9
• Sitting  LW 10-12
• Visually impaired  B 1-3

Letter-number codes identify the athlete’s specific competitive category that is their sport class. LW (Locomotion Winter) refers to winter athletes with a locomotive disability, and B (Blind) refers to athletes who are visually impaired.

The results of a competition are based upon a time handicap system. A mathematic formula applies a percentage (factor) to each athlete based upon their classification so that athletes with the highest level of disability receive a larger time bonus to create an equitable competition. The athlete’s "real time" is multiplied by percentage to determine their final "calculated" time. Therefore, the athlete who completed the race in the fastest "real time" may not be the winner.