Nearly two-thirds of the states have required public employees to contribute more to their pension plans since 2009, The National Association of State Retirement said in a report issued Wednesday.

Missouri and Florida had never required workers to chip in for their pensions, but are now requiring contributions to shore up their state budgets, the group noted.  

In another development, Pennsylvania has joined Arizona, Iowa, Kansas and Nevada in basically mandating workers contribute more when their plan investments fare poorly and less when returns soar.