Fannie Mae & Freddie Mac single-family loan-level data

Free, but registration-gated and not exercised here

The GSE single-family loan-level datasets are free (no fee, including for academic use), but bulk download from both Fannie Mae and Freddie Mac requires a no-cost account and a click-through terms acceptance. The public landing portals are reachable (HTTP 200), but the data files sit behind the login wall, so the end-to-end pull was not exercised from this session. The page therefore carries no provenance badge: it documents the datasets and the access path. A researcher registers once (free) and downloads directly.

The Fannie Mae and Freddie Mac single-family loan-level datasets are the two government-sponsored enterprises’ public releases of acquisition and monthly performance records for the single-family mortgages they bought. Each loan has origination characteristics (FICO, LTV, DTI, rate, term, purpose, geography) and a monthly performance history (delinquency status, prepayment, default, losses). They are the standard free microdata for US mortgage credit-risk and performance research. Used in, for example, Rehbein & Rother (2025), where 1.27 million GSE 30-year fixed-rate mortgages (2000 to 2008 originations, observed to 2018) supply loan-level LTV, rate, delinquency, and default.

• Cost: free (no fee; free account and terms acceptance required to download).
• API key: none (bulk file download behind a registration portal).
• Coverage: Freddie covers roughly 55 million mortgages originated from 1999 through the latest quarterly cutoff; Fannie’s window is comparable. Both append new origination quarters over time.
• Granularity: one acquisition/origination row per loan, plus monthly performance rows per loan.
• Portals (browser): Fannie Data Dynamics https://capitalmarkets.fanniemae.com/tools-applications/data-dynamics · Freddie via Clarity Data Intelligence https://www.freddiemac.com/research/datasets/sf-loanlevel-dataset

Access

Both GSEs publish the data through a free registration portal. There is no anonymous direct link to the bulk files.

• Fannie Mae distributes the Single-Family Loan Performance Data through Data Dynamics. After a free account and terms acceptance, the portal offers a one-click download of the full Acquisition file and the full Performance file, in CSV.
• Freddie Mac distributes the Single Family Loan-Level Dataset through Clarity Data Intelligence. After a free sign-in (the data is free for non-commercial and academic use), the download page offers the full dataset, the Standard dataset by year, the Non-Standard dataset, sample files, and an RPL mapping file. Files are pipe-delimited.

The public documentation (user guides, file-layout and data-dictionary PDFs, FAQs) is generally readable without an account; the loan-level files and even the sample files are behind the login.

Gotchas (the ones that bite pipelines)

• Two file types per GSE, joined on the loan id. Acquisition (one static row per loan, captured at origination) and Performance (one row per loan per month). Do not expect a single combined table; the performance file is the large one.
• Format differs between the two GSEs. Freddie’s files are pipe-delimited (|), no header, with a fixed column order set by the layout document. Fannie’s Data Dynamics export is CSV. Column order, field set, and missing-value conventions differ, so do not reuse one schema for the other.
• Click-through terms, so no anonymous fetch. An automated pull must carry a session cookie obtained after accepting the terms; there is no static URL to the zips. Plan for a one-time human registration.
• Quarterly vintages that grow. Acquisition files are partitioned by origination quarter and new quarters are appended over time, so any hardcoded “latest quarter” logic rots. Record the vintage you pulled.
• Freddie Standard vs Non-Standard. The Non-Standard dataset adds loans excluded from Standard (for example certain modified, ARM, or balloon loans); the RPL mapping file tracks reperforming loans. Choose deliberately rather than mixing them.
• Scale. Tens of millions of loans and a monthly panel on top; the performance files are tens of gigabytes uncompressed. Stream or chunk; do not load whole.
• Host bot-blocking on top of the login. The Fannie capitalmarkets host returns HTTP 403 to automated requests even before the login, so scripted navigation needs a real browser session, not just an authenticated cookie.

Reference

Field	Value
Fannie portal	Data Dynamics (capitalmarkets.fanniemae.com/tools-applications/data-dynamics)
Freddie portal	Clarity Data Intelligence (freddiemac.com/research/datasets/sf-loanlevel-dataset)
File types	Acquisition (per loan) + Performance (per loan per month)
Fannie format	CSV
Freddie format	Pipe-delimited, no header
Freddie coverage	~55M loans, 1999 to latest quarterly cutoff
Key required	No key, but free registration + terms acceptance

Citation

Cite each GSE dataset separately: Fannie Mae, “Single-Family Loan Performance Data,” and Freddie Mac, “Single Family Loan-Level Dataset,” each with the vintage (origination-quarter range and performance cutoff) and retrieval date. Note in a methods appendix that access required free registration, since the files are not anonymously downloadable.