There are varying degrees of exemptions for the ACA rules for plans that had been force prior to the year 2014. These plans that were Grandfathered in had to be in effect from March 23rd 2010 so there are some rules that apply could be exempt from many other rules.
The Grandfathered plans could stay in force forever provided there still offed by the provider and don’t make substantial changes to the health plan. These plans are ever decreasing in numbers because of the normal turnover in the type of insurance products offered. No businesses have been permitted to purchase any new grandfathered plans since March 23rd of 2010 yet employees that are eligible can still enroll in any existing grandfathered health plans.