The Departments of Health and Human Services, Labor, and the Treasury issued proposed regulations regarding the Patient Protection and Affordable Care Act’s (ACA’s) 90-day waiting period limitation. Under this provision of the ACA, group health plans cannot impose a waiting period that exceeds 90 days. A waiting period is defined as the period that must pass before coverage can become effective for an employee or dependent who is otherwise eligible to enroll under the terms of the health plan. This 90-day waiting period limitation becomes effective for plan years beginning on or after January 1, 2014. For purposes of counting days during a waiting period, all calendar days are counted. The waiting period cannot be extended beyond 90 days even if the 91st day happens to fall on a weekend or a holiday. Although the regulations clarify that eligibility conditions that are based solely on the lapse of a time period are permissible for no more than 90 days, a plan may impose other eligibility requirements not based on elapsed time so long as they are not designed to avoid compliance with the 90-day waiting period limitation. For example, requiring a participant to be in an eligible job classification or achieve job-related licensure requirements would not generally be considered a violation of the 90-day waiting period limitation. The regulations also provide guidance on the imposition of waiting periods on variable hour employees. Plans that condition a variable hour employee’s eligibility on meeting certain hour requirements may utilize a measurement period similar to the measurement period used for determining a variable hour employee’s full-time status under the ACA’s shared responsibility provisions. Under these provisions, an employer may track a variable hour employee’s hours during a reasonable measurement period of no more than 12 months. Assuming the variable hour employee worked a sufficient number of hours during the measurement period, the employee’s coverage would have to become effective the earlier of 13 months from the date of hire (plus if the employee’s date of hire is not the first day of the month, the time remaining until the first day of the next calendar month), or 90 days following the end of the measurement period. In light of these regulations, employers should review the eligibility provisions for their health plans to confirm that any waiting period does not exceed 90 days.