Dale Kleber, a veteran lawyer, had been unemployed and job hunting for three years when he came across a position that seemed promising, except for this part of the ad: “3 to 7 years (no more than 7 years) of relevant legal experience,” it said.

Kleber, 58 at the time, had decades of experience, including as general counsel at Dean Foods and, most recently, as CEO of a dairy products trade group. But his efforts to land a new job at that level had been unsuccessful, and he didn’t want to draw down his retirement accounts to make ends meet.

So the Hinsdale, Ill., man applied for the advertised senior counsel position in the Vernon Hills office of medical technology company CareFusion, hoping to use his expertise in corporate transactions. He was never called in for an interview.

Eventually Kleber sued, claiming the seven-year experience cap discriminated against older applicants.

“You look at a job, a job you can do and do well, and you’re precluded from that strictly because you’ve been around the block a few times,” Kleber, now 62, said recently. “The impact was clearly that just about anyone over 40 wasn’t going to be considered, and I thought that was discriminatory.”

Many graying job seekers feel they are overlooked for positions because of their age, even as people stay in the workforce longer to shore up their savings or because better health allows for it. The share of people 55 and older who are working has doubled over the past 25 years, and the trend shows signs of accelerating. The population of working adults who are 65 or older is expected to rise by 75 percent between now and 2050, compared with just 2 percent growth for workers ages 25 to 54.

Sometimes discrimination is overt, such as job ads that explicitly request an age range. But recent litigation has taken on hiring practices that can hurt older applicants in subtler ways, such as through experience caps or targeted job ads that only show up only in certain people’s social media feeds.

“While blatantly age-based job ads have disappeared, many employers continue to engage in practices that are almost as obviously age-based,” Laurie McCann, senior attorney with the AARP, testified last year to the Equal Employment Opportunity Commission. Specifying a minimum number of years of experience for a position is legitimate. “Specifying a maximum number of years of experience has a clear disparate impact on older applicants,” McCann said.

Kleber’s case, now before the U.S. 7th Circuit Court of Appeals in Chicago, raises a critical question about whether job applicants can pursue such lawsuits at all. The federal Age Discrimination in Employment Act prohibits discrimination against people over 40, but there is dispute about whether Congress intended for the law to protect external job applicants, not just current or former employees, against policies that appear to be neutral but have a disproportionate adverse effect on older people.

Federal appeals courts have been split on the issue of whether or not applicants can pursue such age discrimination claims, which makes it likely the case could end up before the Supreme Court.