Revisions include expanded income limits, a cap on home prices, additional documentation requirements and prohibitions against claims by dependents. Qualified repeat buyers can obtain credits up to $6,500. For both the first-time and repeat buyer program, the credit is equal to 10% of the purchase price of the house, up to a maximum of either $6,500 or $8,000. * Members of the armed forces, as well as diplomatic and intelligence personnel serving in foreign countries, will get an extra year to buy a principal residence and still qualify for a credit. They will have until April 30, 2011, to enter into a contract, and until June 30, 2011, to close on it. * Anyone who buys a house after Nov. 6 — even those who had intended to get in the door before the previous Nov. 30 expiration date for the $8,000 credit — will now need to comply with several new rules. First, the house cannot cost more than $800,000. Second, no one under age 18 can claim the credit no matter what the circumstances. And finally, anyone who is counted as a dependent on another taxpayer’s federal filings is ineligible for a home purchase tax credit. * The expanded income limits for purchasers after Nov. 6 range to $125,000 in “modified adjusted gross income” for single taxpayers and to $225,000 for those who file jointly. Singles with incomes between $125,000 and $145,000 may be eligible for reduced credit amounts, as are joint filers with incomes from $225,000 to $245,000. Anyone with an income above these amounts cannot qualify for either of the credits. Under the pre-Nov. 6 rules, taxpayers applying for the $8,000 credit were limited to incomes of $75,000 (single filer) to $150,000 (joint filer). Some taxpayers seeking the extended $8,000 credit are uncertain about co-purchase and co-signing situations, especially involving parents and adult children. When a home-owning parent co-signs for a mortgage with a son or daughter, and both names appear on the note, can the son or daughter qualify for the first-time purchaser credit? The IRS says the parent does not qualify for any portion of the credit since he/she already owns a principal residence. But if the child has not owned a house during the three years preceding the current purchase, and qualifies on income, he or she can be allocated the entire $8,000 credit. Similarly, when unmarried individuals co-purchase a house, and only one of them is eligible for the credit, the full $8,000 can be allocated to the eligible buyer.