Private mortgage insurance

Private mortgage insurance is typically required when down payments are below 20%. Rates can range from 1.5% to 6% of the principal of the loan based upon loan factors such as the percent of the loan insured, loan-to-value (LTV), fixed or variable, and credit score.[1] The rates may be paid annually, monthly, in some combination of the two (split premiums).
Borrower-Paid Private Mortgage Insurance (BPMI or "Traditional Mortgage Insurance")
is a default insurance on mortgage loans provided by private insurance companies and paid for by borrowers. BPMI allows borrowers to obtain a mortgage without having to provide 20% down payment, by covering the lender for the added risk of a high loan-to-value (LTV) mortgage. The US Homeowners Protection Act of 1998 requires PMI to be canceled when the amount owed reaches a certain level, particularly when the loan balance is 78 percent of the home's purchase price. Often, BPMI can be cancelled earlier by submitting a new appraisal showing that the loan balance is less than 80% of the home's value due to appreciation (this generally requires two years of on-time payments first).

Lender-Paid Private Mortgage Insurance (LPMI)
Similar to BPMI, except that it is paid for by the lender, and the borrower is often unaware of its existence. LPMI is usually a feature of loans that claim not to require Mortgage Insurance for high LTV loans. The cost of the premium is built into the interest rate charged on the loan.