Ohio Rev. Code Ann. § 124.271

Any employee in the classified service of the state or any county, city, city health district, general health district, or city school district who is appointed to a position under section 124.30 of the Revised Code, and either demonstrates merit and fitness for the position by successfully completing the probationary period for the position or remains in the position for a period of six months of continuous service, whichever period is longer, shall become a permanent appointee in the classified service at the conclusion of that period.