A limited non-assessment period is a period of time in which a large employer will not be charged a penalty under the employer shared responsibility requirement (employer mandate) even if it’s not offering coverage to a full-time employee.
The new hire waiting period and, if applicable, orientation period, is different from the limited non-assessment period. It’s possible that the combined orientation period or hours-worked requirement plus the new hire waiting period could exceed 90 days, but if the employer is not offering coverage by the first day of the fourth month to a full-time employee, a penalty will apply if that employee is receiving a premium tax credit.
The initial measurement period (of up to 12 months) is also a limited non-assessment period. It only applies to part-time / variable-hour employees.