The health insurer Humana is considering a potential sale of itself after several competitors approached it, people briefed on the matter said Friday.

Humana is working with bankers at Goldman Sachs to explore its options, said these people, who were not authorized to speak publicly. They added that the company had made no decisions and might decide against a sale. A deal would continue a wave of mergers throughout the health care industry.

Any deal for Humana would be expensive: The insurer had a market value of about $28 billion before the Wall Street Journal reported on the company’s deliberations.

Other rivals are of similar size. Cigna has a market value of about $36 billion, while Aetna is valued at about $42 billion. Both have been seen as potential suitors.

Shares of Humana jumped more than 20 percent Friday, reaching highs untouched in two decades.

Representatives for Humana were not immediately available for comment. A Goldman representative declined to comment.