Once you've filed the FAFSA, your work may not be done. That's because there's another financial aid form, the CSS Profile. The Profile is used by about 400 private colleges to allocate their own financial aid dollars. The FAFSA and the Profile have a lot of similarities, but also some key differences.

Like the FAFSA, the Profile uses parent income and assets and student income and assets to determine a family's ability to pay, and assesses each at different rates in calculating Expected Family Contribution. But it considers a slightly broader range of assets, including:

• Home equity

• Cash value of insurance policies including non-qualified annuities

• All 529s for which the student is the beneficiary, not just those owned by the parents

• In most cases, both parents' income and assets if the parents are divorced

• The value of small businesses owned by the parents

In addition, the CSS Profile allows colleges to include supplemental questions which can range from what cars the family drives and whether they're owned or leased to what majors the student is interested in.

The CSS Profile also gives colleges leeway in using the different elements of the formula. Home equity is one such element: some colleges disregard it completely, others cap it at a multiple of the parents' income, and others use the full value. The formula uses the Federal House Price Index, not Zillow or other such tools, which incorporates purchase date and local factors into its calculations.)

The Profile has some additional flexibility beyond the FAFSA's: it incorporates some of a family's actual expenses into its formula rather than simply a number based on household size, and it gives opportunities to explain your circumstances in greater detail, which can be very helpful to families who have one-time items in their FAFSA or Profile data.

Most-- but not all-- families will have a higher EFC on the Profile than on the FAFSA. The College Board has an EFC estimator for the Profile, similar to the Department of Education's Student Aid estimator. However, the school-to-school differences in calculations mean it's truly an estimate.

The CSS Profile and FAFSA differ in two other very important respects:

• The Profile is only used to allocate institutional aid dollars, not federal dollars. That means that you'll have to file the FAFSA, too, in order to be considered for a Pell grant, work study, or federal student loans, and any grant programs available in your state. It also means you don't have to rush to file the Profile because your submission will be reviewed when your application is reviewed.

• The Profile costs money to submit: $25 for the first school and $16 for each additional school. That means you should only submit it when you apply to a college.

Many people think of the Profile as the FAFSA for private colleges, but in fact a fairly limited universe of colleges requires it. How do you know if you need to file it? The Common App will tell you when you load a college into it, you can look at the college's financial aid web page, or you can check this list.

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