This topic provides information on commingling ARMs, including:
ARMs originated under the same ARM plan may have original terms up to 30 years and may be commingled in the same ARM pool.
ARMs originated under different ARM plans cannot be commingled in the same pool. In certain cases, however, lenders may be permitted to pool seasoned ARMs in ARM plans with shorter initial fixed-rate periods. Interested lenders should contact their Fannie Mae customer account team to determine what flexibility may be available for a specific situation.
ARMs originated under a single ARM plan, but with different post-conversion disposition options (market rate option or take-out option) cannot be included in the same pool.