Prepayments on Fannie Mae and Freddie Mac mortgage-backed securities slowed in December and January, suggesting HARP 2.0 has yet to stimulate mass-refinancing activity, analysts said Tuesday.

Total prepayments for Fannie Mae MBS fell to a constant repayment rate of 20.7% in January from 22.8% in December and 24.4% in November, analyst firm Keefe, Bruyette & Woods said in a report.

For Freddie Mac, all prepayments declined to 22.5% from 24% in December and 25.4% in November.

"While this data reinforces our view that organic refinance activity has peaked, if rates decline from current levels, it could lead to an increase in prepayments in the coming months," wrote KBW analysts Bose George, Jade Rahmani and Ryan O'Steen.

The CPR on Fannie's 30-year, fixed-rate MBS fell to 21.6% from 23.6% in December and 25.2% in November, while the 15-year FRM MBS fell to 18.9% from 20.9% in December and 23.2% in November.

The CPR on Freddie Mac's 30-year, fixed-rate MBS fell to 23.4% from 24.8% in December and 26.2% in November. Meanwhile, the 15-year, fixed rate averaged 20.8%, down from 22.6% in December and 24.7% in October, the KBW report said.

Hybrid MBS prepayment speeds also declined in January for both GSEs.

While HARP 2.0 was expected to lead to a boon in refinancing activity, analysts with Royal Bank of Scotland Group noted that the slowing in January prepayments could reveal "the poor showing of HARP 2.0 so far."

"The muted prepayments indicate that busy mortgage lenders may still be facing with the often complicated and time-consuming process of building infrastructure, such as soliciting those HARP eligible borrowers," RBS analysts noted.

Still, the RBS report suggested barriers keeping borrowers from the HARP program will eventually be lifted, making it possible for HARP 2.0 to still have a significant impact in the MBS segment in the future.

"We expect February prepayments to continue increasing due to lower rates and the possible increase in HARP refinancing activities," the RBS report said. "Since it may take several months for lenders to ramp up their efforts and invest resources to actively solicit these borrowers, we don't expect HARP 2.0 to be fully up to speed in the near future."