"Our decision does not reflect a lack of confidence in the economy," Fed Chair Janet Yellen said at the start of her press conference. "Since monetary policy is only modestly accommodative, there appears little risk of falling behind the curve in the near future."
Stocks climbed with Treasuries after the decision, while the dollar declined and gold rallied. The Standard & Poor's 500 Index extended gains after the Fed's statement, while a gauge of the U.S. yield curve flattened as the shortest-maturity debt underperformed. The greenback lost ground against all but two of its major peers.
The central bank's so-called "dot plot," which it uses to signal its outlook for the path of interest rates, showed that officials expected one quarter-point rate increase this year. Three policymakers projected that keeping rates unchanged this year would be most appropriate. Officials scaled back expectations for hikes in 2017 and over the longer run.
Policymakers see two rate hikes next year, down from their June median projection of three.
The Fed said that the labor market will "strengthen somewhat further," adding the qualifier "somewhat further" to similar language from the July statement.
"Although the unemployment rate is little changed in recent months, job gains have been solid, on average," the Fed said in its statement. "Household spending has been growing strongly but business fixed investment has remained soft."
The target range for the benchmark federal funds rate remains at 0.25 per cent to 0.5 per cent, where it's been since a quarter-point increase in December 2015 that ended seven years of near-zero rates.
The Fed repeated that it "continues to closely monitor inflation indicators and global economic and financial developments."
The FOMC reiterated that borrowing costs will probably rise at an "only gradual" pace. Policymakers also reiterated that they expect inflation to rise to their 2 per cent goal over the medium term.
Because November's FOMC meeting comes within a week of the U.S. presidential election and isn't followed by a press conference with Yellen, economists have viewed the Fed's December meeting as a more likely candidate for an increase.
The latest decision could embolden Republican presidential nominee Donald Trump to unleash additional attacks on Yellen. The billionaire businessman said last week that the Fed "is being totally controlled politically" and might stand pat on rates for the rest of year.
Yellen, a former economics professor at the University of California at Berkeley, was appointed Fed chair by President Barack Obama and served as President Bill Clinton's top economic adviser.
The decision comes as Fed officials become more convinced that the economy is experiencing a new normal.
Policymakers scaled back their median projection of the long-term interest rate to 2.9 per cent from 3 per cent in June. The estimate shows how high officials think rates can climb, so its downgrade suggests a shallower hiking cycle.
Fed officials also cut their median growth projection for 2016 to 1.8 per cent from 2 per cent, mirroring the drop in the longer-run forecast, based on median estimates. Inflation is projected at 1.3 per cent in the fourth quarter, down from a forecast of 1.4 per cent in June. Policy makers again projected that inflation will reach the 2 per cent target in 2018.
Most economists in a Bloomberg survey had expected the committee to stay on hold, assigning just a 15 per cent chance of a hike this month. Fed watchers saw a 54 per cent probability that the Fed will raise rates at its December 13-14 meeting.
Nonfarm payrolls have climbed by 182,000 jobs on average so far this year, although the most recent report showed a cooling to 151,000 job gains along with moderating wage increases. Other figures have shown declines in August retail sales and industrial production, as well as drops in sentiment at service companies and manufacturers.
Inflation is still running below the Fed's 2 per cent goal. After picking up earlier in the year, annual gains in the headline personal consumption expenditures price index slowed to 0.8 per cent in July. Core inflation, which excludes food and fuel costs, is firmer though still undershooting at 1.6 per cent.
Meanwhile, inflation expectations have stayed relatively low. A gauge of market-based expectations watched by the Fed is projecting a pace of price gains of about 1.5 per cent in the period five to 10 years out.
The Fed repeated that "market-based measures of inflation compensation remain low."