Mortgage rate shift sparks jump in loan defects

Defects in residential U.S. mortgage loans increased in the early months of 2026 as mortgage rates declined and refinance volumes grew, according to newly released industry data.

The industry-wide critical defect rate climbed to 1.71% in the first quarter, reflecting a notable increase from 1.38% in the fourth quarter and 1.31% a year ago, according to Aces Quality Management, a mortgage compliance firm.

“The increase was the largest quarter-over-quarter rise in four years, but its composition matters more than its magnitude,” said the company’s quarterly report on trends in underwriting and loan processing defects, published Tuesday.

In fact, underwriting improved across the majority of defect categories linked to borrower qualification, reported Aces, while defects increased in categories related to “compliance, documentation and property-related findings.”

A critical defect is an issue in a loan file that would result in the loan being uninsurable or ineligible for sale, while the critical defect rate represents the share of loans reviewed post-closing that possess at least one critical defect.

Aces compiles its analysis and defect statistics from post-close loan audits chosen by lenders for full-file reviews, categorizing its findings using Fannie Mae’s loan defect taxonomy.

A critical shift

As lenders and underwriting teams positioned themselves for growing refinance momentum in early 2026, it shifted capacity toward workflows and loan types “that the rate environment appeared to support,” Aces noted. In late February, the Iran war moved the goalposts.

“The reversal arrived within weeks, leaving pipelines that had already tilted toward refinance operating in an environment that no longer favored refinance growth,” said the report.

For the second consecutive quarter, legal, regulatory and compliance defects emerged as the leading driver of loan files flagged for full reviews. They accounted for about 26% of all defects, up from 24.6% the previous quarter and representing the highest share in more than five years.

Income- and employment-related issues ranked second among defect categories, accounting for about 20% of defects, followed by asset-related defects at slightly above 10%. Asset defects declined from 15%, however, after three consecutive quarterly increases.

“After years as the industry’s most persistent defect driver, it’s encouraging to see income/employment out of the top spot for a second straight quarter,” Nick Volpe, executive vice president of Aces, commented in the report.

Volpe also noted that defects “migrate,” underscoring the rise of legal, regulatory and compliance defects for multiple quarters. Credit defects declined to 5.2% from 5.38%, while loan documentation defects rose to 8.55% from 7.17%.

While purchase transactions remained dominant in review share, the refinance share grew for a fourth straight quarter, reaching its highest level in four years. Refinance review share climbed to about 32% from 27.4%, though refinance defect share rose more slowly, from 36.8% to roughly 38.6%.

As refinance volumes accelerated, purchase review share fell from 72.6% to 68%, while purchase defect share also decreased from to 61.4% from about 63.2%.

Across various loan types, the defect share on conventional loans that satisfy Fannie Mae’s and Freddie Mac’s underwriting guidelines rose to 57.2%, while defect share on loans insured by the Federal Housing Administration increased to 32.3%. The defect share on loans backed by the Department of Veterans Affairs declined to about 9.8%.