i think you can usually keep about one upgrade behind on medisoft and based on awful customer service from McKesson I dread upgrading but with impending ICD 10 and such I feel I have to upgrade. I laugh because when I first bought Medisoft I paid less than $500 to buy and now version upgrades are 600-700.
If you buy from Medisoft directly they include no support in $650 fee - including getting it to install. If it won't install they want several hundred more to help. I have heard some VAR offer some support and don't do this to you so wanted to see.