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How to Calculate the FMLA's 12-Month Period

Federal law allows employers to choose from four methods

A calendar on a wooden floor in front of a blue wall.


​Employees covered by the Family and Medical Leave Act (FMLA) may take up to 12 weeks of unpaid leave in a 12-month period for qualifying medical conditions. Employers should note that they can measure the 12-month period in several ways. The method that makes the most sense may depend on the business. Here's what employers should know about their options. 

Be Consistent

Under federal law, employers may select one of four ways to establish the 12-month period—so long as it is uniformly applied to all employees taking FMLA leave:

  • The calendar year.
  • Any fixed 12-month period (such as a fiscal year or the period starting on an employee's anniversary date).
  • The 12-month period measured forward from the date an employee's FMLA leave begins.
  • A rolling 12-month period measured backward from the date an employee uses any FMLA leave.

Employers need to make sure that the method they use is clearly identified in a written policy, said Craig O'Loughlin, an attorney with Snell & Wilmer in Phoenix and Orange County, Calif. "Employers that fail to identify the method in play will be stuck with whichever method is the most beneficial to the employee."

It is important to note that some states require employers to use a specific method for determining the leave period. "The employer may comply with the state provisions for all employees within that state and uniformly use one of the four methods for all other employees," said Felicity Fowler, an attorney with McGinnis Lochridge in Dallas and Houston.

Fixed Period

There are some advantages to using one of the first two methods and selecting a fixed 12-month period. If the employer is concerned mainly about ease of administration, then using a fixed period may be an attractive option because it is easy to track, said Terry Dawson, an attorney with Barnes & Thornburg in Indianapolis. The employer simply determines the amount of leave used within the year and doesn't need to look backward or forward.

An employer will be able to use the same fixed date to calculate the 12-month period for all employees, Fowler said.

However, a fixed-period calculation makes it possible for employees to stack together up to 24 weeks of consecutive leave spanning two separate leave years. For example, if an employer uses a calendar year to calculate the 12-month period, an eligible employee could take FMLA leave from October to December in 2018 and 12 additional weeks starting on Jan. 1, 2019, because a new 12-month period has begun.

The employer wouldn't be able to limit such leave based on an operational hardship except in very limited situations involving key employees, noted Casey Kurtz, an attorney with Littler in Pittsburgh. 

Measuring Forward

Under the third method, an employer would calculate the 12-month period by measuring forward from the first date an employee takes leave. The employee would be eligible for 12 weeks during that forward-looking time frame, Dawson explained.

Then, the next 12-month calculation would begin the first time the employee takes FMLA leave after that period expires. So if an employee began leave on July 2, 2018, he or she would be eligible to take 12 weeks of leave between July 2, 2018 and July 1, 2019. The next leave period would start on the first day of leave beginning on July 2, 2019, or thereafter. 

Measuring Backward

The final method is calculated on a rolling basis looking backward to the immediately preceding 12 months. So if a worker takes leave on July 2, 2018, the employer would tally how much FMLA time the employee took since July 3, 2017, to determine eligibility.

Each time an employee takes FMLA leave, the remaining leave entitlement would be the balance of the 12 weeks which has not been used during the immediately preceding 12 months, Fowler explained.

[SHRM members-only how-to guide: How to Calculate the FMLA Rolling Year Method]

The primary disadvantage of this method is that it requires more administrative time to track, she noted. The employer must keep good records of when employees take FMLA time off—even if it is in small increments—so that the employer can review all of the FMLA absences in the prior 12-month period and deduct those absences from the employee's available time remaining, she said.

Though complex, this method prevents employees from stacking time off from one period to the next and has other benefits for employers.

Employers that manage the rolling period and continually calculate the available FMLA time stand to benefit the most from this method, because it is more effective at preventing FMLA abuse and minimizes the burden on the company's operations, O'Loughlin said.

"Increasingly, employers are contracting with third parties to handle FMLA leave on their behalf, which can lessen the administrative burden that might otherwise prompt them to choose a leave year that is less cumbersome to track," Kurtz noted. 

Changing Methods

An employer must follow certain steps if it decides to change its calculation method. For instance, if the employer is currently using a fixed calendar year method and wants to change to a rolling lookback period, the employer must give workers at least 60 days' notice before adopting the new approach.

Additionally, employees can't lose out on any leave eligibility due to the change. So the transition must take place in such a way that workers retain the full benefit of their leave entitlement under whichever method affords the greatest benefit to them, Fowler said.