A hybrid INFONAVIT + bank mortgage: you combine your housing sub-account with a bank loan to reach the amount you need. It's useful when your INFONAVIT entitlement doesn't cover the price. The bank charges its market rate on its portion, INFONAVIT charges its own — cheaper than a pure bank mortgage, but pricier than INFONAVIT on its own.
Cofinavit combines your Infonavit credit with a bank one to reach a larger home amount. You add your housing sub-account to the down payment and the bank covers the rest. It helps when Infonavit alone doesn't reach what you want to buy and you have provable formal income.
It doesn't always pay off: the Infonavit portion can carry a different rate than the pure bank loan, and the mix adds paperwork and timelines. Run the numbers on both options — pure bank mortgage versus Cofinavit — with each CAT in view. For strong-income, clean-Buró profiles the pure bank loan is sometimes cheaper; Cofinavit shines when you need the sub-account's push for the down payment.