Requirements for a HECM Reverse Mortgage

What are the Basic Requirements for a HECM Reverse Mortgage?
There are five basic requirements:
1. Age - one borrower must be 62 or older
2. use - the home must be the primary residence
3. equity - the home must have sufficient equity
4. credit
5. income
If you've been turned down for a Reverse Mortgage before. now is a great time to have another look. the market and guidelines are constantly changing and you may qualify now.

[@spectator1123]

By your example, if the 400K represents 50% of the home's equity, wouldn't a reverse mortgage in essence payoff the mortgage?