It's a terrific time to buy a home, but not because homes happen to affordable.

It's a terrific time to buy because the variety of mortgage products available to home buyers looks poised to shrink.

Monday, Alt-A mortgage lender IndyMac Bank stopped accepting mortgage applications and it's likely that other Alt-A lenders will likely follow suit.   

Alt-A loans are ones in which borrowers can't (or won't) verify one of two major underwriting criteria:

• Evidence of income
• Evidence of assets

Since the Credit Crunch began last July, Alt-A mortgages have been a steady source of funds for "in-between" borrowers -- those that are not quite prime, and not quite sub-prime.  IndyMac was among the largest lenders of its type and had outlasted many of its peers. 

Its position as a market leader and subsequent exit from lending means that the remaining Alt-A lenders will likely make one of two choices in the coming weeks:

1. Raise rates and fees because of greater Alt-A mortgage risk, or
2. Follow IndyMac's lead and exit mortgage lending altogether

Both outcomes would be harsh for home buyers of all types because when any large bank takes mortgage-related losses like IndyMac just did, it tends to create major risk aversion in the market.

Risk aversion impacts everyone -- even the "good" borrowers. 

Banks have been nervous about lending for several months and so they'd rather pass on an "average" mortgage application rather than risk getting stuck with a potentially "bad" one.  IndyMac's exit may cause fewer mortgages to get approved.

In other words, buyers eligible for financing today may be ineligible tomorrow. 

Therefore, if you're a home buyer and you know your credit profile is less-than-ideal, consider writing a purchase contract sooner rather than later.  Your mortgage options may be thinning, and the ones you have may be getting more expensive.