The Internal Revenue Service has published an eagerly awaited final rule that could affect efforts by employers to offer more flexibility to older workers.

The final rule, “Distributions From a Pension Plan Upon Attainment of Normal Retirement Age,” affects large employers with defined benefit pension plans that want to let older employees start collecting pension benefits while working past the normal retirement age.

The definition of “normal retirement age” is important in applying pension plan rules, and it affects matters such as preventing discrimination against newer employees or lower-paid employees, officials write in a preamble to the final rule, which appears today in the Federal Register.

Officials ended up deciding to offer a safe harbor “normal retirement age” of 62.

Employers also can have a 2-part normal retirement age, which might set the later of age 62 or the fifth anniversary of plan participation as the normal retirement age, officials write.

In most cases, the normal retirement age cannot be later than the later of age 65 or the fifth anniversary of the time the participant joined the plan, officials write.

Plans can use a normal retirement age of 50 for public safety employees, such as firefighters.

Administrators of most other plans have to show reasonable facts and circumstances for a plan’s industry to justify setting the normal retirement between 55 and 62.

Outside of the public safety sector, administrators can set the normal retirement age below 55 only if they can demonstrate that is a reasonably representative retirement age for the industry of the relevant covered workforce, officials write.

A copy of the final retirement age rule is on the Web