Job hopping is a way of life for many professionals, especially millennials who balk at the notion of staying with one company for their entire career. While moving from one job to the next to get ahead is acceptable, particularly for younger workers, it’s how you do the jumping that matters.“Everyone is allowed one or two instances of ‘bad fit,’ in which case you change jobs after a year or less, but in general, you should aim to stay with a company for at least two years,” says Aravinda Rao Souza, senior marketing manager at Bullhorn, a recruitment software company. “You want a chance to put down roots somewhere and really get to know a specific business.” Younger workers in their 20s will be given more leeway if they’ve made a lot of career changes. But once you hit your 30s experts say recruiters and hiring managers are going to be less forgiving to job hoppers.When it comes to job hopping, J.T. O’Donnell, founder and chief executive of CAREEREALISM, a career advice and job search magazine, says there are two types of people. There are the serial hoppers whose entire career is made up of one or two year stints. Then there are the job hoppers who went through a rough patch when leaving one company and trying to find their ideal job elsewhere. Often those people make a couple of jumps before they find the one job they stay at for a while.If you fall into the latter category it will be easy for you to explain what happened and for hiring managers and recruiters to look past the hops. But if you are a serial job hopper, you will have a tougher time convincing employers that you are someone they should invest in. O’Donnell says people should aim to stay at their job for four or five years before moving on. “For the first two years you are developing…and after five years you are looking for progression,” she says.According to a survey conducted by Bullhorn, 39% of recruiters said the single biggest obstacle for an unemployed candidate is having a history of “job hopping,” or voluntarily leaving a company before one year even if the person keeps moving up. “When I see that someone has hopped jobs and gotten increasingly better titles with each new job, it’s a gigantic red flag for me as a hiring manager,” says Souza. “It shows me that they weren’t doing good enough work to get promoted within a single organization, so they had to climb the corporate ladder by continually going somewhere where they have no history.”For people who made a couple of wrong choices, the best thing they can do is be ready to have an honest explanation of why they did some hopping. Mary Marino, founder of EmployementPipeline.com, says the job candidate has to be able to substantiate why the job hopping was necessary. For instance, if there was no room to grow within the company, or if the job turned into something that wouldn’t further their career are two valid reasons for making some changes. “Since previous job history is only one of many metrics used by employers to predict new hire commitment levels, I wouldn’t say it’s frowned upon or expected,” says Marino. “What is expected however is that job changes be thoroughly explained and are clearly in the best interest of the candidate’s career advancement.”One of the worst things job seekers can say during an interview to explain away job hopping is, “I’m always looking for another opportunity,” says Jeffrey Agranoff, principal at accounting firm Friedman. Using that statement as an explanation will actually back fire instead of helping. “It’s a very popular answer lately but to me it’s an automatic turn off,” he says. “It doesn’t show loyalty. Why would I hire somebody who is always looking?”At the end of the day, the best thing people can do to advance their career and avoid hopping from one job to the next is to think strategically about their employment. That means before you accept any job, inquire about your progression within the firm. For instance is there a way to move up or will you be doing the same role in three or five years from now. You also want to work for a company that provides you the opportunity to enhance your existing skills and learn new ones. “It’s really about communications and having a game plan,” says O’Donnell. “If you can’t move forward at your current employer, then carefully choose your next employer to have that opportunity to grow.” Growing by switching companies is not the solution, she says.