[Official Guidance]

Text of IRS Notice 2012-59, Guidance on 90-Day Waiting Period Limitation Under Public Health Service Act Section 2708 (PDF)
"Consistent with PHS Act section 2708, eligibility conditions that are based solely on the lapse of a time period are permissible for no more than 90 days. Other conditions for eligibility under the terms of a group health plan are generally permissible under PHS Act section 2708, unless the condition is designed to avoid compliance with the 90-day waiting period limitation.... If a group health plan conditions eligibility on an employee regularly working a specified number of hours per period (or working full time), and it cannot be determined that a newly hired employee is reasonably expected to regularly work that number of hours per period (or work full time), the plan may take a reasonable period of time to determine whether the employee meets the plan's eligibility condition, which may include a measurement period that is consistent with the timeframe permitted for such determinations under Code section 4980H ... whether or not it is an applicable large employer subject to section 4980H.... Employers, plans and issuers may rely on the compliance guidance in this notice at least through the end of 2014." (Internal Revenue Service)

[Official Guidance]

Text of IRS Notice 2012-58, Determining Full-Time Employees for Purposes of Shared Responsibility for Employers Regarding Health Coverage (PDF)
"This notice describes safe harbor methods that employers may use (but are not required to use) to determine which employees are treated as full-time employees for purposes of the shared employer responsibility provisions of Section 4980H of the Internal Revenue Code (Code). Specifically, the administrative guidance in this notice, modifying and expanding on previous guidance, includes a safe harbor method that employers may apply to specified newly-hired employees.... [This notice] this notice (1) Expands the safe harbor method described in a previous notice to provide employers the option to use a look-back measurement period of up to 12 months to determine whether new variable hour employees or seasonal employees are full-time employees, without being subject to a payment under Section 4980H for this period with respect to those employees.... (2) Provides employers the option to use specified administrative periods ... for ongoing employees ... and certain newly hired employees ... (3) Facilitates a transition for new employees from the determination method the employer chooses to use for them to the determination method the employer chooses to use for ongoing employees; and (4) Provides employers reliance, at least through the end of 2014, on the guidance contained in this notice and on [certain specified] approaches described in prior notices[.]" (Internal Revenue Service)