Generally speaking, yes, but you need to check on your state specific laws. I am in PA. In PA, if you are not a broker or working under a broker you cannot manage the properties of others. One strategy of protection is separating properties in to one entity and management into another.
I am in the process of doing this transition currently and should be done by the end of the year. The LLC that is the PM company will have 5% stake in the holding company so that there are no issues with PA law. The positive is separation of duties and protection the downside is more paperwork, two sets of bank accounts etc. However, a positive in addition to this is that I am also undertaking management of some friend's units with the new PM LLC. They are providing a small equity stake in properties I take over at no cost in exchange for discounted PM service. As I scale, with the idea of bringing on a partner or two and extracting myself from day-to-day PM work long term to focus on acquisition, parsing out these business functions makes even more sense.