Arch Mortgage is introducing a second lien mortgage insurance pricing program in New Mexico, with a requested effective date of April 20, 2026. The filing covers lender paid monthly premium plans for closed end loans, open end loans, and separate versions for credit unions.

The program is built for second mortgage loans, including closed end seconds and HELOCs, and is designed to protect lenders against borrower defaults. Arch said the product can cover up to 100% of the unpaid principal balance on an individual loan, plus accumulated interest at the time a claim is submitted or required to be submitted, and up to 25% of attorney fees.

The filing adds five new documents: closed end and open end second lien programs, credit union closed end and open end programs, and a new set of rating rules and definitions. Rates vary by combined loan to value and borrower credit score, with the highest annualized lender paid monthly premiums showing up in the riskiest bands. For example, in the standard open end program, rates for loans with CLTV between 95% and 90.01% range from 1.20% for borrowers with 800+ credit scores to 2.75% for those in the 660 to 679 range.

Arch also built in flexibility. Its rating rules allow premium adjustments of up to plus or minus 25% based on factors such as expected duration of coverage, loan characteristics, property characteristics, lender characteristics, expense characteristics, and mortgage market conditions.

In its actuarial memorandum, Arch said it does not have recent origination experience with this product and instead relied on standard financial models and legacy second lien data. The company said it will monitor performance and file amended rates later if needed.