Each cooperative has their own set of income and credit requirements whether you are putting down a 10% downpayment or 20% downpayment. Buyers in a coop who put down 20% will show greater financial stability and avoid paying PMI. Given the recent tightening of the credit markets, you will see larger downpayments required by lending institutions. Sponsored units (or unsold shares) have less restrictive requirements because there is no board approval process. For more information on coops, please read The New York Co-op Bible: Everything You Need to Know About Co-ops and Condos: Getting In, Staying In, Surviving, Thriving.