Homebuying became less affordable in May, as rising mortgage rates and accelerating loan amounts caused the Mortgage Bankers Association’s Purchase Applications Payment Index (PAPI) to increase 2.2%.

The MBA’s index, which tracks monthly mortgage payments relative to borrower income, climbed to 159.4 in May from an even 156 in April, indicating declining affordability.

On a dollar basis, the national median payment applied for by purchase applicants increased to $2,198 last month from $2,152 in April.

“The decrease in affordability was widespread, with conditions declining in 33 states,” noted Edward Seiler, MBA’s associate vice president of housing economics, in a press release. “While affordability conditions remain improved compared to a year ago, the monthly increase underscores how sensitive prospective homebuyers remain to changes in interest rates and home prices.”

The highest PAPI readings and lowest affordability were observed in Idaho (254.1), Nevada (231.5), Rhode Island (213.1), Arizona (209.1) and Florida (200.4).

The lowest PAPI scores were enjoyed by homebuyers in Louisiana (121.7), Washington, D.C. (123.1), Connecticut (124.9), Alaska (128.6) and Maryland (132.2).

Median mortgage payments rose for both conventional and government borrowers. Conventional loan applicants paid a median of $2,211 in May, up from $2,166 in April. Borrowers with loans backed by the Federal Housing Administration saw median mortgage amounts of $1,873 last month, up from $1,829 in April.

But in the silver linings department, the PAPI is down 4.4% on an annual basis, with median payments decreasing 0.6% year over year in May and household earnings growing at a 4% clip.