When Michaela Mendelsohn, the owner and chief executive of the Pollo West Corporation, arrived at her restaurant company’s holiday party in 2006, it had been a year since she had seen most of her 500 employees. In that time, she had worked from her home in the Conejo Valley of Southern California and was in contact with only a handful of staff members.

A rumor had circulated that she was dying of cancer. But in fact, she was transitioning from male to female, including undergoing facial and body surgeries and changing her style of dress to one she describes as very feminine.

Feeling both nervous and excited, she stood up and introduced herself to her staff. “They had no idea who I was,” Ms. Mendelsohn said, adding that their reaction was largely supportive.

But Ms. Mendelsohn’s experience was atypical. Most transgender people cannot take a hiatus from their workplace while they transition, nor do they have the options of someone who owns the company.