The decision of 85-year-old Pope Emeritus Benedict to resign due to a “lack of strength in mind and body” reflects challenges faced by employers and employees as America’s workforce ages.

While his predecessor Pope John Paul II was a symbol of perseverance, Pope Emeritus Benedict is being hailed by some as a model of pragmatism for his decision. He is the first pope to step down in nearly 600 years.

There are few jobs with lifetime guarantees of employment — popes, federal judges and perhaps some business owners are among the few who face the quandary of deciding for themselves “when to call it a day.” A federal judge I clerked for heard cases well into his mid-90s. A different “John Paul” — Supreme Court Justice John Paul Stevens — retired from the Supreme Court in 2010, at age 90.

Advances in medicine and economic realities mean that more Americans either need or want to work past the traditional retirement ages of 65 or 70. As an employment law attorney, I saw many age discrimination claims by middle managers in their late 50s in late 1990s. These days, I am seeing more claims by workers in their 70s. I believe this trend will continue.

By law, employers cannot terminate or refuse to hire someone simply because he or she is 75, 80 or 85 years old, or any particular age for that matter, once he reaches age 40. If an employer believes that the physical or mental consequences of aging are affecting an employee’s ability to perform her job, the employer should document the performance issues objectively.

The employer may also need to determine if an accommodation under the Americans with Disabilities Act might address the issue. Diversity benefits employers. Older workers have much to offer, and a right to keep working if they wish to do so.

Mandatory retirement is the opposite of a job guaranteed for life. Policies requiring retirement, however, are rare, and potentially illegal. Minnesota state court judges, priests and bishops, airline pilots, air traffic controllers, and some military and law enforcement positions are among the exceptions where mandatory retirement policies are allowed.

Pilots successfully lobbied to have their mandatory retirement age raised from 60 to 65 under the Fair Treatment for Experienced Pilots Act of 2007.

The federal Age Discrimination in Employment Act originally protected only workers ages 40 to 65. The upper age was briefly bumped up to 70 and then eliminated completely. Now, under federal law, employers can implement mandatory retirement policies only in situations where it can be shown that a “bona fide occupational qualification” is reasonably necessary to the normal operation of the business. Court rulings have made it clear, however, that a “bona fide occupational qualification” defense succeeds only rarely.

A second, narrow exception exists also for executives and employees in high policymaking positions who are over 65 and entitled to participate in a qualified retirement plan. While Minnesota state law allows mandatory retirement for employees 70 and over, federal law generally trumps this provision.

The U.S. Equal Employment Opportunity Commission (EEOC) received 22,857 charges of age discrimination in fiscal year 2012, up from 14,141 in 1999. This represents more than a 50 percent increase in just over a decade. Demographics and the aging baby boom generation are likely to drive these numbers even higher.

This means employers need to accept older workers and avoid age discrimination litigation. They must avoid ageist questions in job applications and interviews, train managers and supervisors on anti-discrimination policies, review policies and plans, and analyze the effects on older workers when planning any reduction in force. The law can create liability for age discrimination even without intent on the part of the employer if there is a statistical “disparate impact” on older workers.

No single, correct answer may be given to the question, “When is the right time for me to retire? To go part time? To go back to work? To start a new career?”

Each of us must make our own decision, with input from family, friends and colleagues. It should be informed and deliberate. The law has made this decision largely our own.