Middle Class Mortgage Insurance Premium Act of 2021

This bill increases the income limit for deducting mortgage insurance premiums on federal income taxes. It raises the cap from $100,000 (single filers) / $50,000 (joint filers) to $200,000 / $100,000 annually, making this higher limit permanent. The change directly affects homeowners who itemize deductions and pay private mortgage insurance (PMI) premiums. The amendment applies to tax years beginning after December 31, 2021, as specified in the bill text.