“It’s fundamental to the way the law works,” the aide said. “You have to have it eventually.”

The penalties collected from employers that don’t provide healthcare are expected to raise about $140 billion over the next 10 years, so Congress and the White House probably couldn’t afford to keep delaying the mandate, or to repeal it altogether.

But the revenues are limited in the first year, making a one-year delay more palatable. The employer mandate was also designed to prevent employers from dropping coverage more than it aimed to bring new people into the system.

Judith Solomon, vice president for health policy at the Center on Budget and Policy Priorities, a liberal policy group, predicted the delay will have little effect on coverage.