Most home buyers need a down payment of 3.5% to 20% of the purchase price to qualify for a mortgage.

A few can still get away with putting no money down through one type of government-guaranteed loan.

A few may have to come up with more than 20% to buy very expensive homes or condos in overbuilt markets burdened with foreclosures such as Miami.

But most buyers will fall somewhere in between the extremes -- and that's good.

A down payment ensures you have some equity in your home -- that's the difference between what your home is worth and how much you owe on the mortgage.

Far too many borrowers who bought their homes with no down payments during the real estate bubble are now underwater, owing more on their mortgages than their homes are worth.

They can't sell. They can't refinance. And they're defaulting by the hundreds of thousands.

Although lenders are fussier today, the clock hasn't turned back 20 or 30 years to when lenders demanded 20% down payments from everyone.

Here's what you have to do to get a loan with:

No down payment.

There's only one way to get 100% financing for a home today, qualify for a loan guaranteed by the Department of Veterans Affairs.

Veterans, including members of the National Guard and reserve units, soldiers on active duty and widows whose spouses' deaths were war-related, are all eligible for these government-guaranteed mortgages.

Although VA loans don't require mortgage insurance, they do impose a one-time funding fee that can be rolled into the loan. If you're purchasing your first home and putting no money down, you'll pay 2.15% of the loan amount.

The funding fee is usually waived for widows and vets with service-related disabilities.

Click here for more information on VA loans.

A 3.5% down payment.

Getting the Federal Housing Administration to guarantee your loan can hold your down payment to as little as this.

FHA loans do require mortgage insurance covered by an up-front premium that can also be added to the principal.

This insurance is used to cover any losses lenders might incur if you default and costs 1.75% of the borrowed amount. That will increase to 2.25% this spring.

Click here to learn more about FHA loans.

A 5% to 20% down payment.

Most lenders require minimum down payments of 5% for conventional loans not guaranteed by VA or FHA.

To qualify for that, you'll need to be purchasing a single-family home in a neighborhood where property values are more stable than average, and every aspect of your finances will need to be above average.

If you're buying in a market where home values are still suffering significant declines, lenders will require at least a 10% down payment.

Expect to be asked for anywhere from 10% to 15% down if your:

• FICO credit score is below 740 (the average is about 730).
• Housing costs will be more than 28% of your gross income.
• All of your debt payments will consume more than 36% of what you make.

You'll also have to qualify and pay for private mortgage insurance.

Some borrowers who win approval from their bank or finance company are being rejected for PMI because insurers are actually demanding higher credit scores and lower debt-to-income ratios than lenders.

Click here to learn more about private mortgage insurance.

A 20% down payment.

If your credit score is below 700, most lenders will require a down payment of at least 20%.

Same for anyone buying a condo regardless of their credit score. We've heard of lenders demanding down payments of up to 50% in distressed markets such as Miami.

Jumbo loans are those that are too big to be bought by the two, government-owned companies that provide more than 70% of the money for home loans in this country.

Fannie Mae (the Federal National Mortgage Association) and Freddie Mac (the Federal Home Loan Mortgage Corp.) are prohibited from buying loans larger than $729,750 in high-cost areas like New York and San Francisco and much less in most other markets.

That means banks must fund those loans out of their own money or sell them to private investors who demand higher down payments, usually 25% or more.

Some help exists for low-to-moderate-income homeowners who will have the most trouble saving for a down payment.

Congress recently ended the private down payment assistance programs you may have heard about, because too many borrowers who took advantage of them were defaulting on their loans.

But state-sponsored mortgage programs are still an option for those who can meet the strict limits on how much applicants can earn and spend on a home.

By Bonnie Biafore

Interest.com Contributing Editor