The agency said JN.1, which is an offspring of BA.2.86, is now the most widely circulated variant in the US and globally, Reuters reported.
It is also the dominant variant in Europe and is rising sharply in Asia, the CDC said.
The predicted range of 55% to 68% of cases is an increase from the estimated prevalence of 39% to 50% of cases in the US projected by the CDC as of Dec. 23.
The CDC said currently there is no evidence that JN.1 causes more severe disease and added current vaccines are expected to increase protection against JN.1.
COVID-19 hospitalizations increased 20.4% in the week ended Dec. 30, the CDC said.
In December, the World Health Organization classified JN.1 as a "variant of interest" and said current evidence shows risk to public health was low from the strain.