NEW YORK, Jan 23 (Reuters) - Unemployment rates increased in 15 U.S. states in December, a rise from the prior month, but was unchanged in the majority of states and the District of Columbia, a report showed Tuesday.

Nonfarm payroll employment levels, meanwhile, remained essentially unchanged in all states last month from November, according to Bureau of Labor Statistics data. From a year earlier, employment rose in 30 states while remaining essentially unchanged in 20 others and DC.

Massachusetts and Rhode Island experienced a 0.3 percentage point increase in unemployment, the greatest month-over-month rise among states. Minnesota's unemployment rate fell by 0.2 percentage point, the only state to experience a decrease.

Maryland and North Dakota had the lowest jobless rates at 1.9%. Nevada had the highest unemployment rate, remaining unchanged from November's 5.4%.

The national unemployment rate was unchanged at 3.7% in December, the report said. The economy added 216,000 jobs in December, up from November's 173,000 added. (Reporting by Amina Niasse; Editing by Dan Burns)