National HealthCare Corp., one of the oldest long-term healthcare companies in the United States, received a warning letter from the American Stock Exchange last month because it has a board member who is not yet independent from the company.

Board member Richard F. LaRoche, Jr. was the executive officer of the company less than three years ago. The company is in violation of a stock exchange requirement because it does not have a majority of independent directors on its board. The letter gives the company until May 31 to regain compliance with Amex requirements.

According to National Healthcare, the incident will be corrected when LaRoche becomes independent on May 22. That day marks the passing of the third anniversary of the date he resigned as executive officer of the company.