The September US Services Purchasing Managers' Index conducted by Markit came in at 54.9 percent, down 0.2 from the final August estimate of 55.1.

Here is the opening from the latest press release:

Commenting on the latest survey results, Chris Williamson, Chief Business Economist at IHS Markit, said:

“The service sector showed further signs of struggling amid the COVID-19 Delta wave in September. While business activity is growing at a rate in line with the long-run average seen prior to the pandemic, this represents a marked downshifting from the spring and summer months.

“High virus case numbers have not only subdued demand for many services, notably among consumers in the hospitality sector, the pandemic continues to hit the labor market both in terms of staff absences amid the spread of the virus and low labor market participation rates
meaning it is difficult to fill vacancies.

“With COVID-19 cases numbers appearing to have peaked early in September, the situation in terms of demand and labor supply should start to improve as we head into the fourth quarter; a sentiment supported by business optimism rising in the service sector to the highest since
June and an unprecedented strong build-up of back orders.” [Press Release]

Here is a snapshot of the series since mid-2012.

Here is an overlay with the equivalent PMI survey conducted by the Institute for Supply Management, which they refer to as "Non-Manufacturing" (see our full article on this series here). Over its history, the ISM metric has been significantly the more volatile of the two.

The next chart uses a three-month moving average of the two rather volatile series to facilitate our understanding of the current trend. Since early in 2016, the ISM metric has shown stronger growth than the Markit counterpart.