For the most part, you must have some sort of hardship (lost job, health issues, decline in revenues/pay, bankruptcy, etc). Next, a potential loan modification will depend on several variables including but not limited to the outstanding loan amount, how many loans there are (1st, 2nd and sometimes 3rds), who the owner of the loan is (not necessarily the bank as they are often just the servicing company acting on behalf of the investor that actually owns your loan), where your property is located, what the recent comparable sales in your neighborhood are, whether the property is your primary residence, how much income you have, can you document it, and are you behind on your payment.
Depending on your answer to most, if not all, of these questions will depend on whether you qualify. A lot of it boils down to a negotiation, which is where an experience lawyer can help. My law firm handles loan modifications. We do work in California and have referral lawyers in Nevada, Pennsylvania, New Jersey and Delaware. Our phone number is 310-780-8275 and our website address is www.sbaylaw.com.