It depends. I went through a few year period shortly after my ticket where due to time and money I went into "skills maintenance mode". I only flew 12-15 a year, but was able to maintain reasonable proficiency. That was because every flight was between .6 and 1.1 hours, and about half involved just manuevers, slow flight, stalls, etc., and pattern work (practice area was close). The other half was typically taking friends for rides. That meant a flight every two to three weeks. Later I was able to increase my hours by flying as a safety pilot to more experienced members in a flying club I joined, which was helpful as well.
During my "skills maintainence mode" I logged next to no XC time, but I did keep myself feeling reasonably comfortable in the cockpit. For example, .6 hours doesn't seem like a lot, but when its spent staying in the pattern doing x-wind landing after x-wind landing, you get a fair amount of acquired confidence for the money and time invested.