Out of Sync: The Hidden Risk of Misaligned Federal FMLA and Washington PMFL Leave Periods

The federal Family and Medical Leave Act (FMLA) and Washington’s Paid Family and Medical Leave (PFML) both provide employees with job-protected leave, but they operate under different rules and timelines. Washington employers managing both FMLA and PFML face the challenge of understanding not only how each law measures leave time, but also how their leave periods interact.

Recent updates to PFML notice requirements and the growing overlap between PFML and FMLA have created a timely opportunity for employers to reconsider how they calculate the FMLA 12‑month leave period. For many organizations, these developments call into question long-standing leave management strategies.

FMLA’s 12‑Month Calculation: Employer Choice, Employee Protection

Under FMLA, eligible employees are entitled to up to 12 weeks of job‑protected leave in a 12‑month period. While that entitlement is fixed, the law gives employers flexibility in defining the 12‑month period.

Employers may choose from four permissible options:

• The calendar year,
• Any fixed 12‑month period (such as a fiscal year or anniversary date),
• A 12‑month period measured forward from the first day of FMLA leave, or
• A rolling 12‑month period measured backward from the date leave is used.

If an employer decides to change its method, it must provide at least 60 days’ notice to employees. Importantly, during the transition, affected employees are entitled to the most beneficial calculation under either method. Employers may not change calculation methods to interfere with or deny FMLA rights.

Historically, many employers have favored the rolling backward method because it prevents the ability to “stack” leave across year‑end. But as PFML increasingly overlaps with FMLA, that perceived advantage has become far less clear.

PFML’s Benefit Year Operates Differently

Washington’s PFML program does not use or allow any of the FMLA’s four calculation options. Instead, PFML operates on a benefit year that:

• Begins on the Sunday of the week in which a complete PFML application is filed, and
• Ends 52 weeks later on a Saturday.

Backdated PFML claims are allowed only in limited circumstances, typically requiring good cause or for the Employment Security Department’s (ESD) administrative convenience, and employees must still comply with strict filing deadlines. If an employee has multiple qualifying events within the same benefit year, they must reopen the existing claim rather than start a new one.

Because of this structure, PFML and FMLA leave periods are rarely perfectly aligned, even when both apply to the same qualifying event.

New PFML Notices Change the FMLA–PFML Relationship

Recent PFML notice requirements significantly shift how employers can coordinate job-protected leave under PFMLA and FMLA. For the first time, employers have a clear mechanism to prevent the stacking of job‑protected leave by running PFML job protection concurrently with FMLA.

Key points employers should understand:

• Employers still may not force employees to apply for PFML.
• Employers may now run PFML job protection concurrently during FMLA leave.

To do so, employers must provide a specific written notice:

• Within five business days of an employee requesting or taking FMLA, and
• At least monthly thereafter.

This notice must identify the employer’s chosen FMLA 12‑month calculation method. Critically, the notice instructions also require employers to explain how the timing of FMLA leave relates to the PFML claim year, creating new pressure to ensure internal consistency, clarity, and defensibility in leave administration.

Rethinking the Assumed Advantages of Rolling Backward

While rolling backward has long been considered the gold standard for controlling leave abuse, it comes with substantial administrative challenges, especially when paired with PFML.

Under a rolling backward method, FMLA eligibility changes daily, while prior leave usage remains fixed in time. This makes it difficult to explain calculations, particularly to employees taking intermittent leave or transitioning from intermittent to continuous leave.

Rolling backward is often justified as the only effective way to prevent stacking. But in reality:

• A measured-forward method also prevents stacking, because the 12‑month period does not begin until FMLA leave actually starts.
• The stacking risk under a measured-forward method is limited and requires deliberate employee planning.
• A measured-forward method aligns more closely with PFML’s structure, even if perfect alignment is impossible.

With PFML job protection now able to run concurrently with FMLA, the risk calculus has changed, and employers should reassess whether the complexity of rolling backward still delivers meaningful value.

Practical Recommendations for Employers

Employers reevaluating their FMLA calculation method should consider the following steps:

• Evaluate whether a measured-forward method would simplify administration and improve alignment with PFML.
• Provide at least 60 days’ notice before changing methods and identify employees who would need to be grandfathered during the transition.
• Train HR staff carefully on how PFML benefit years intersect with FMLA eligibility and leave tracking.
• Accept that perfect alignment is impossible—PFML benefit years may not start on the first day of FMLA leave, and ESD may retroactively designate PFML in limited cases.
• Focus on clarity, consistency, and compliance defensibility over theoretical stacking concerns.

Final Thoughts

The relationship between FMLA and Washington PFML continues to evolve. New notice requirements—and the ability to coordinate PFML job protection with FMLA—mean that longstanding assumptions about rolling backward calculations deserve a second look.

For many employers, simplifying administration, improving employee understanding, and reducing compliance risk may outweigh the traditional benefits of complex leave calculations. The key question is no longer “What have we always done?” but rather, “Does our current FMLA calculation method still make sense in a PFML world?”

Eligible members with questions are encouraged to contact HR Chat, the Hotline and access resources in mozzo.