When any portion of an unincorporated area of a county is to be annexed or incorporated into a city, code city, or town and layoffs will result in the county sheriff's office, employees so affected shall be notified of their right to transfer. The affected employees shall have ninety days after the commencement of the thirty-six month period as specified in RCW 35.13.380(3) to file a request to transfer their employment to the police department of the city, code city, or town under RCW 35.13.360 through 35.13.400.