Shares of home health providers continued to slide Monday in the wake of investigations by regulators.

Four publicly traded home health companies are being investigated by the Securities and Exchange Commission, which is looking into reports that they made unnecessary visits to some patients. By visiting patients a tenth time, the companies could get an additional $2,200 in Medicare revenue per patient.

The SEC began looking into Amedisys Inc. and Almost Family Inc. on July 1. Gentiva Health Services and LHC Group Inc. disclosed inquiries from the agency last week. All four companies say they are cooperating with the investigations and subpoenas.

The Senate Finance Committee launched an investigation in May.

In afternoon trading, shares of Almost Family lost $1.41, or 5.5 percent, to $24.19. Earlier the shares set a new year low of $23.85. Amedisys shares slipped 97 cents, or 3.7 percent, to $25.05. They earlier reached a low of $24.50.

Shares of Gentiva lost $1.31, or 5.9 percent, to $20.98, while LHC Group stock shed $1.04, or 4.7 percent, to $21.

So far this month, Amedisys shares are down 40.8 percent, Almost Family shares have fallen 26.7 percent, Gentiva stock is off 17.5 percent, and LHC shares have declined 20.6 percent.