21st Century Housing Act

21st Century Housing Act - Amends the Housing Act of 1948 to authorize the Secretary of Housing and Urban Development, in carrying out any program through the Federal Housing Administration, to: (1) appoint and fix the compensation of Administration personnel; and (2) use premium-generated income for information technology upgrades.

Amends the National Housing Act to: (1) extend the maturity term for insured mortgages; (2) revise mortgage insurance eligibility criteria and requirements for premium charges; (3) authorize waiver of certain requirements for new product initiatives; (4) increase the maximum mortgage amount limit for multifamily housing in high-cost areas; and (5) increase the capital ratio for the Mutual Mortgage Insurance Fund.