"Within separations, the quits level and rate increased to a series high of 4.4 million and 3.0 percent, respectively", the department said in its JOLTS, or Job Openings and Labor Turnover, report.
The total number of job openings barely changed in September, with 10.4 million positions available at a rate of 6.6%, the JOLTS report showed.
The Federal Reserve said in its Beige Book report for October that demand for workers was high in an economy rebounding aggressively from the coronavirus pandemic, but that labour growth had also been constricted by a low supply of available people.
Child care issues and vaccine mandates were among the main reasons for people quitting, the Fed said, as working mothers were unable to afford child care due to incomes or spending power falling during the pandemic, while political and other beliefs prevented many from receiving COVID-19 shots as a condition for staying on the job.
The United States lost more than 21 million jobs between March and April 2020, at the height of business lockdowns prompted by the coronavirus. At least five million of those jobs have yet to return, officials say.