The Justice Department wants more information about CVS Health’s proposed $8 billion acquisition of Signify Health before allowing it to proceed, the companies disclosed Thursday. 

CVS announced last month that it plans to buy Signify Health, the nation’s largest provider of home health risk assessments. The deal would represent the Aetna parent company’s first foray into the lucrative home health market, an area in which rival Medicare Advantage carriers UnitedHealthcare and Humana already have a foothold. CVS has also indicated that it is in the market for a primary care provider. 

The Justice Department request extends the amount of time CVS Health and Signify Health must wait to consummate the deal by 30 days, although the government could waive that requirement. CVS still expects to close the transaction in the first half of next year, according to documents filed to the Securities and Exchange Commission Thursday. Neither company immediately responded to interview requests. 

Amazon, UnitedHealth Group and Option Care Health also sought to acquire Signify Health, which leveraged their bids to more than double its value over three months of talks.

The federal government has been taking a close look at a number of healthcare mergers. The Federal Trade Commission asked for more information on UnitedHealth Group’s proposed $5.4 billion acquisition of home health provider LHC Group in June and last month asked for additional information about Amazon’s proposed $3.9 billion purchase of primary care provider One Medical, for example.