The state’s unemployment rate continues to drop as reflected in March’s 3.4 percent jobless rate.

The Maine Department of Labor released preliminary figures Friday that show March’s rate is slightly lower than February’s 3.6 percent rate and significantly below the 4.6 percent rate of March 2015.

The U.S. preliminary unemployment rate of 5.0 percent was little changed from February and down from 5.5 percent one year ago.

Although falling unemployment numbers are usually hailed as an indicator of an improving economy, Maine essentially achieved full employment in February. Many employers say the tight labor pool is making it harder to hire qualified applicants.

The size of the available workforce is also shrinking, a reflection of people who have retired, given up finding work, moved out of state, been laid off or otherwise are no longer counted in the state’s labor pool.

March unemployment rates for New England were also below the national average, coming in at 4.5 percent. Rates for other states were 2.6 percent in New Hampshire, 3.3 percent in Vermont, 4.4 percent in Massachusetts, 5.4 percent in Rhode Island and 5.7 percent in Connecticut.

Not seasonally adjusted, the statewide unemployment rate estimate of 4.2 percent for March was down from 5.4 percent one year ago. The metro area unemployment rate was below the statewide average in the Portland-South Portland (3.1 percent) and Lewiston-Auburn (3.8 percent), and close to the average in Bangor (4.1 percent).