Here is what an offering of a GNMA looks like. I think you can do better in CDs.

Charles Schwab & Co. Inc., is pleased to announce the
availability of the following new issue Taxable Offering:


Issuer Name: Government National Mortgage Association GNMA II
Issuer Description: G2 3953. Cusip 36202EMA4. Available on
schwab.com. New pool with 1.0 factor, subject to availability.
Government National Mortgage Association (GNMA) or "Ginnie
Mae" is an agency of the U.S. government. The agency buys
qualified mortgage loans, securitizes the loans, and distributes
the securities. Ginnie Mae pools are backed by the full faith
and credit of the U.S. Government."Average life” is the
average number of years that each dollar of principal remains
outstanding. It represents the amount of time it takes to
receive back approximately half of your principal. This
estimate can vary with interest rates and is based on prepayment
assumptions that may or may not be met. "PSA" is a
benchmark used to evaluate mortgage prepayment speeds. Investors
may experience a gain or loss due to prepayment of obligations,
and will receive back part or all of their investment before
maturity. See www.ginniemae.gov for additional information.
Type Of Bond/Security: Asset/Mortgage-backed Security

Investment Amount: 25000 Face Min/1000 Face Increments
Coupon Rate: 5.50%
Expected Offering Price: 100 PAR
Anticipated Yield to Average Life: 5.512%
Anticipated Average Life: 7.737 years
PSA Speed Assumption: 195 PSA
Anticipated Final Maturity: 2/20/2037
Payment Frequency: Monthly