I work in Ohio and have been told by my employers that I CANNOT make a pattern (3 or more in a 90 day period) of taking vacation and/or sick time off around my already scheduled days off. Is this legal on their part or can I take my vacation time any time I want to?

It is perfectly legal. There is no law permitting an employee to take vacation time "any time he wants to".

Patty's answer is correct in all 50 states. In no state does the law give the employee permission to take vacation time any time he wants. In all states the employer controls the work hours, and that includes vacation time.

Thank you for your response to my question. I still cant believe that they can tell me when I can take vacation.

Barring a legally binding contract or CBA that specifically says otherwise, it is ALWAYS up to the employer when an employee can take vacation. Some employers may allow you to decide, but that is their choice, not a legal requirement.

Look at it this way. If there were going to be a law mandating that the employer let the employee take vacation any time they wanted, that law would have to apply to everyone, right? It couldn't apply to just some employees and not others. If it's a law, it's for everyone. So what would stop all tax accountants from taking vacation the week of April 15? What would stop all airline gate attendants from taking vacation Thanksgiving week? What would stop all sales clerks from taking vacation the Friday after Thanksgiving, or Christmas Eve?