How are small PT clinics managing AR without a dedicated billing team?

We are a 2 location practice. No in-house biller, Owner does most of it with help from front desk.

AR is honestly all over the place. We collect at time of service okay but everything past 60 days is kind of a black hole. I know there's money in there. I just don't have the bandwidth to chase all of it consistently..Looked at outsourcing billing but the percentages scared me a little for where we're at volume-wise. Curious how other smaller practices are handling this. Do you outsource, keep it in house, some combo? And what does your denial follow up actually look like day to day?