However, even that decline is likely overly optimistic.
The cutoff date for survey responses was March 18, before the worsening outbreak in New York City forced the deployment of a Navy hospital ship and the construction of field hospitals in Central Park, and before data showed 3.3 million Americans filing for unemployment benefits in a single week.
The index measuring sentiment six months ahead of time plunged nearly 20 points to 88.2, according to the report.
"Consumer confidence declined sharply in March due to a deterioration in the short-term outlook," said Lynn Franco, The Conference Board's head of economic indicators.
Franco warned that more bad news is likely ahead, and the survey showed double the share of respondents -- just under 15 percent -- expecting business conditions to worsen in the next six months.
The "intensification of COVID-19 and extreme volatility in the financial markets have increased uncertainty about the outlook for the economy and jobs. March's decline in confidence is more in line with a severe contraction -- rather than a temporary shock -- and further declines are sure to follow," she said.
The results of the monthly survey also are subject to revision, as late-arriving responses are incorporated.
The University of Michigan survey released Friday showed the virus battered the consumer sentiment index, which plunged 11.9 points to 89.1, worse than expected and the fourth-largest monthly drop in nearly 50 years.