WASHINGTON — The Obama administration's mortgage relief plan has helped only about 16 percent of borrowers who signed up since its launch last year, and hundreds of thousands of homeowners are in limbo without an answer.

The Treasury Department said as of last month, about 170,000 homeowners had completed the application process and had their loan payments reduced permanently. That compares with nearly 1.1 million homeowners who have enrolled since the plan started.

About 90,000 homeowners have dropped out so far, either because they failed to make payments or didn't return paperwork.

The program is designed to lower borrowers' monthly payments by reducing mortgage rates to as low as 2 percent for five years and extending loan terms to as long as 40 years.