An expanding patchwork of paid sick leave laws may represent the next challenge for employers trying to keep pace with changing workplace laws.

While Congress has failed to pass federal legislation guaranteeing paid leave to private sector employees, that hasn’t slowed the trend. Connecticut, California, Massachusetts, Oregon, Vermont and the District of Columbia have adopted laws requiring private sector employers to provide paid sick leave to their workers. Proposed laws also were introduced in 2015 in New York, Virginia and Wisconsin and an initiative is underway in Michigan to get it on the November 2016 ballot. More than 15 cities, including New York, Seattle, San Francisco, and Portland, already have paid leave laws on the books, and several more have them under consideration.

The trend toward paid sick leave laws may well require employers to abandon the common practice of bundling various vacation, sick, and personal leave days into a single Paid Time Off bank that employees can use for any purpose. Instead, they may need to accrue and separately account for paid sick leave. Employers with PTO banks may have to award additional sick days, unless their current PTO policy allows employees to use the same amount of leave for the same purposes and under the same conditions as required by the particular sick leave law, and also satisfies the accrual, carry-over, and use requirements of that law. Those accrual, carry-over and use requirements vary considerably from law to law.

Employers with employees in multiple jurisdictions with differing paid sick leave requirements, may still opt to use a PTO policy, provided they ensure that it meets the requirements of the most generous paid sick leave law. However, employers should note that many paid sick leave laws have specific record-keeping requirements that would require separately tracking sick leave. Further, in some states like California, if an employer does not have sick leave separate from PTO or vacation leave, the employer would be required to pay out all PTO or vacation at the time of separation.

Employers who are currently in the process of changing their record-keeping procedures to adapt to changes resulting from the new salary threshold regulations might also consider adopting new procedures for separately tracking sick leave from other leave at the same time.