According to a story published in the New York Times on Monday, older Americans are signing up for the Affordable Care Act in larger numbers than younger ones.

Only 24 percent of those who signed up for a health insurance plan in the first three months of the program are between the ages of 18-34, a group lawmakers hoped would bolster the system. Individuals ages 55-64, falling right below qualifying for Medicare, make up the largest numbers of enrollment. This raises concerns because there are currently not enough young, healthy people enrolled in the program to offset the costs of older people with greater healthcare needs.

Officials say that 2.2 million people signed up by Dec. 28 for health insurance through HealthCare.gov and the state-based websites. The Administration hopes seven million Americans will sign up by March 31st of this year.