“Put the maximum in your 401(k) if you can,” people like me advise, “and don’t forget to buy disability insurance, because the group plans offered through employers are often a good deal.”

That’s reasonable advice, of course. But for a growing share of the population, it’s simply irrelevant. That’s because more and more people aren’t working full-time for a single employer, with all of the perks and headaches that can entail. Rather, they’re earning income in what has been dubbed by some as the "gig" economy—through alternate work arrangements like independent contracting or providing on-call services (think Uber drivers).