Dexom announced its chief commercial officer, Teri Lawver, will retire at the end of the year

Shares of Dexcom fell 9% in extended trading on Thursday after the company released third-quarter results that beat analysts' expectations but showed a decline in U.S. revenue year over year.

Here's how the company did:

The company's revenue increased 2% to $994.2 million from $975 million a year earlier. Dexcom's U.S. revenue declined 2% from $713.6 million the prior year. The company reported net income of $134.6 million, or 34 cents per share, up from $120.7 million, or 29 cents per share, in the same period last year.

Dexcom offers a suite of tools like continuous glucose monitors (CGMs) for patients who have been diagnosed with diabetes. In August, it launched its first over-the-counter product called Stelo, which is intended for adults who do not take insulin.

The company maintained its full fiscal year guidance and expects revenue of $4 billion to $4.05 billion. Last quarter, Dexcom lowered its guidance from the $4.20 billion to $4.35 billion it forecast in the first quarter.

This lowered guidance and a revenue miss caused Dexcom shares to tumble more than 40% following the release of its second-quarter results in July. The company's CEO Kevin Sayer attributed the challenges to a restructuring of the company's sales team, fewer new customers than expected and lower revenue per user.

Sayer said in a call with investors Thursday that these problems improved during the third quarter.

The company also announced Teri Lawver, Dexcom's chief commercial officer, will retire at the end of the year. Lawver will stay on as an adviser through early next year, and Sayer will lead the commercial organization as Dexcom searches for a replacement.