source:
  type: guide
  id: fnma-sel-c3-5-05
  authority: Fannie Mae Selling Guide C3-5-05 — Commingling ARMs in MBS
  description: Fannie Mae Selling Guide C3-5-05 — Commingling ARMs in MBS.
  coverage_tier: operative
obligations:
- id: fnma-sel-c3-5-05-full
  canonical_id: fnma-sel-c3-5-05-full
  section: Fannie Mae Selling Guide C3-5-05 — Commingling ARMs in MBS
  type: do
  tags:
  - regulator-direct
  - fnma
  - selling-guide
  - corpus-expansion
  - tier-operative
  primary_source:
    tier: 1
    authority: Fannie Mae Selling Guide C3-5-05 — Commingling ARMs in MBS
    source_class: fnma-guide
    source_url: https://singlefamily.fanniemae.com/media/document/pdf/selling-guide
    snapshot_id: 5f7b8b79da595d76
    fetched_at: '2026-05-25T14:09:57Z'
    content_hash: sha256:98cf85a02861bbe84914a0e339b327c8fc131869a8a573882007bbeea60c5701
    paragraph_quote: 'C3-5-05, Commingling ARMs in MBS (02/23/2016) Introduction This
      topic provides information on commingling ARMs, including: ARM Loan Types Lenders
      May Commingle in the Same Pool ARM Loan Types Lenders May Not Commingle in the
      Same Pool ARM Loan Types Lenders May Commingle in the Same Pool Published May
      6, 2026 1007 ARMs originated under the same ARM plan may have original terms
      up to 30 years and may be commingled in the same ARM pool. ARM Loan Types Lenders
      May Not Commingle in the Same 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. Recent Related Announcements There are no recently issued Announcements
      related to this topic. Chapter C3-6, Pooling Loans into Fannie Majors Introduction
      Lenders can pool mortgages into two types of MBS, which includes UMBS: Single-Issuer
      and Fannie Majors. This chapter provides information on pooling loans into Fannie
      Majors.'
  judgment: false
