U.S. retail sales excluding motor vehicles and parts likely posted further gains in September, data from the Chicago Federal Reserve showed Wednesday, though part of the rise probably reflected higher prices.

The Chicago Fed Advance Retail Trade Summary estimated that retail sales excluding autos and parts increased by a seasonally adjusted 0.5% last month after advancing 0.7% in August.

CARTS is meant to offer an early read for the official monthly retail sales data, excluding automobiles, produced by the Commerce Department's Census Bureau.

The comprehensive retail sales report, scheduled for release on Thursday, has been delayed by the government shutdown, now in its third week.

When adjusted for inflation, retail sales excluding autos are projected to have risen only 0.2% last month after increasing 0.3% in August. CARTS' projections are broadly in line with most estimates from independent economists.

Retail sales growth continues to be driven by higher-income households amid robust financial and real estate wealth gains. Their wage growth has remained solid.

Economists say many middle-income consumers are being financially squeezed, though lower-income households are being impacted the most by labor market sluggishness, which is curbing wage growth. This income group has also borne the brunt of higher prices from tariffs on imports.

"Consumers are increasingly fatigued by high price levels and navigating an economy that feels less favorable," said Will Auchincloss, Americas retail sector leader at EY-Parthenon. "We expect to see more intentional spending, with households prioritizing value and necessity over discretionary purchases."

A Bank of America Institute survey showed spending by the lowest-income households grew 0.6% year-on-year in September. In contrast middle- and higher-income household spending increased 1.6% and 2.6%, respectively.

"Middle- and higher-income households have stronger wage growth but higher-income spending is likely also benefiting from wealth effects," Bank of America Institute said.

"The discretionary spending of the top 5% of households by income tends to widen compared to the middle-income cohort when the S&P 500 is rising."