Two weeks after its shares were clobbered when federal officials said its Medicare pilot program isn't producing adequate results, Healthways today responded by saying the model can't be properly evaluated in part because "CMS did not deliver the pilot population that it was contractually obligated to provide."

Commenting on a letter the company has sent to Kerry Weems, the acting administrator of the Centers for Medicaid and Medicare Services, CEO Ben Leedle Jr. said there are still "a number of unresolved issues" with the Medicare Health Support pilot program, but that early results are meeting or beating expectations.

"This level of performance is not surprising to us given that every metric we use to evaluate the operational execution of our programs is exceeding the targets we set specifically for MHS," Leedle said in a statement that also affirmed the company's commitment to the objectives of the MHS program.

Healthways' work on the pilot, which is treating 16,000 patients, is due to wrap up in July. For the company's full statement, click here.

Separately, Fortune is reporting that yesterday's 10 percent drop in Healthways shares was due primarily to concerns that it may lose its Minnesota BlueCross contract. In Wednesday trading, shares of the company closed the regular session up 1.9 percent, but was trading down 3.7 percent in after-hours trading.