The Treasury Department announced Monday that companies with 50 to 99 employees have an additional year to comply with the coverage mandate, until January 1, 2016.
For businesses with 100 or more employees the requirement will still take effect in 2015. But other newly announced provisions may help some of those firms.
The employer requirement was originally supposed to take effect this year for companies with 50 or more workers. The administration delayed it last year, the first sign of potential problems with the rollout of President Barack Obama's health care law.
Under the law, companies with fewer than 50 employees don't have to offer coverage.