The Medic is a Teutonic man of medicine. While he may have a tenuous adherence to medical ethics, he is nonetheless the primary healing class of the team. Although the Medic's Syringe Gun and Bonesaw aren't the most excellent weapons for direct combat, he can typically still be found near the front lines, healing wounded teammates while trying to stay out of battle.

When the Medic focuses his Medi Gun on a teammate, they will gradually regain health points. Teammates who are already at full health will have their health buffed beyond the standard limit, going up to 150% of their base health capacity. Teammates who have not taken damage recently will be healed more rapidly, encouraging other players withdrawals when injured.

When healing, the Medic will gradually fill a unique ÜberCharge bar, which can fill faster if healing injured or not-overhealed teammates. When the ÜberCharge bar is fully charged, the Medic's healing gun will begin to crackle, accompanied by small electric Team-colored particles at the tip of the Medi Gun, indicating that he can now deploy a unique charge to benefit his healing target, and himself, for eight seconds. A charge from the Medi Gun offers temporary invulnerability; a charge from the Kritzkrieg grants the Medic and his healing target guaranteed critical hits; the Quick-Fix grants the Medic and his healing target rapid healing, along with immunity to knockback; the Vaccinator grants the Medic and his healing target enhanced damage resistance to a specific damage type (bullets, explosives, and fire).

Although the Medic cannot heal himself, unless using an ÜberCharge-deployed Quick-Fix, or using the Kritzkrieg's Oktoberfest taunt, he is capable of slowly regenerating health over time, and is the only class capable of doing so naturally. The longer a Medic stays out of combat and avoids taking damage, the greater the increments of health he will passively heal. An injured Medic will begin regenerating health at a rate of 3 health points per second, scaling up over the following ten seconds to a maximum of 6 health per second (this base rate can be positively affected by the Amputator and negatively affected by the Blutsauger).