The Centers for Disease Control and Prevention (CDC) recommends that most (73%) persons residing in the United States be vaccinated against influenza each year. The actual rate of influenza vaccination is substantially below target levels: about 60% of persons >or=65 years (target is 90%) and only 10% to 40% of other groups (target is 60% for younger persons who have risk factors and 60% for healthcare personnel). Vaccinating patients throughout the influenza vaccination season (from October into January and beyond)--providing access beyond the traditional "fall immunization season"--is an important step toward meeting the substantial need for influenza vaccination. Vaccination rates may also be increased by interventions that increase patient demand and access to vaccine and overcome practice-related barriers. Such interventions include vaccination-only clinics, standing orders, strong recommendations from healthcare providers, as well as reminder and recall efforts. For maximum impact on immunization rates, interventions should be combined into a multifaceted immunization program rather than used alone. Interventions that address site-specific needs, taking resources into account, should be implemented on a practice-by-practice basis. With supply of influenza vaccine now plentiful, efforts need to be focused on reducing missed vaccination opportunities and promoting vaccination beyond the traditional fall time frame to protect as many Americans as possible from serious and potentially deadly influenza infection.