VA issued Circular 26-20-20: Index for ARM Products (Circular). The Circular reminds lenders of VA regulations establishing the Constant Maturity Treasury (CMT) rate as the only approved index for ARM products. Lenders must ensure that all ARMs submitted to VA for guaranty comply with 38 CFR 36.4312(d)(1) in the use of CMT.  Alternative indexes are not authorized and are ineligible for guaranty.

For more information, see: https://www.benefits.va.gov/HOMELOANS/documents/circulars/26_20_20.pdf