Jumbo is for a loan above the county's conforming limit, where every lender writes its own rules

A loan is jumbo when the loan amount is above the conforming loan limit for the county the property sits in, and the Federal Housing Finance Agency publishes that limit for San Luis Obispo County every year. San Luis Obispo County is a high-cost area, so its limit is higher than the national baseline. At or below the limit a loan can be conforming and Fannie Mae or Freddie Mac can buy it; above it, the loan is jumbo and the lender sets its own guidelines.

It is a different kind of hard. A jumbo loan is not insured by a government agency and cannot be sold to Fannie Mae or Freddie Mac, so each lender writes its own guidelines for credit, reserves, documentation and the property itself. There is no single standard to clear, which also means a file one lender declines can sit comfortably inside another lender's guidelines without anything about the file changing.

Not necessarily. Because jumbo guidelines are set lender by lender, a decline tells you that one lender's rules did not fit your file, which is not the same as saying no lender will write the loan. A broker can take the same file to other jumbo lenders whose guidelines read it differently. What a decline is useful for is learning which guideline it failed.

Only if the loan amount you need is above the conforming limit for San Luis Obispo County, which the Federal Housing Finance Agency publishes each year. The way to settle it is to work out the loan amount first and compare it with the county's current limit.