42 CFR §411.130

1. (a)CMS responsibility. After CMS determines that a plan has been a nonconforming GHP in a particular year, it refers its determination to the IRS, but only after the parties have exhausted all CMS appeal rights with respect to the determination.
2. (b)IRS responsibility. The IRS administers section 5000 of the IRC, which imposes a tax on employers (other than governmental entities) and employee organizations that contribute to a nonconforming GHP. The tax is equal to 25 percent of the employer's or employee organization's expenses, incurred during the calendar year in which the plan is a nonconforming GHP, for each GHP, both conforming and nonconforming, to which the employer or employee organization contributes.