Do employers rates go up if you claim unemployment?

This answer is specific to unemployment insurance in California:

The California Employment Development Department uses an experience rating system, where employers pay unemployment taxes at rates commensurate with claims activities by their employees. New employers start with an unemployment insurance (UI) rate of 3.4% on the first $7,000 of each employee's annual wages.

Employers with high unemployment activity pay higher unemployment tax rates, and employers with lower activity pay less. The UI rate is adjusted annually. The employer receives notification in December of the new UI rate effective January 1 of the following year.

To answer the question above, any claim filed by a former employee affects the former employer's unemployment experience rating, i.e. UI rate.

See the attached Related Link to the EDD's explanation of the California System of Experience Rating.

FEDERAL: Federal unemployment insurance (FUTA) is also paid on the first $7,000 of each employee's annual wages. The FUTA rate in 2009 was 6.2% but employers who pay into their state unemployment fund (and most all do) receive a maximum credit of 5.4%, resulting in a FUTA rate of .8% (.008) in 2009.

The FUTA rate is fixed and does not change based on the employer's experience rating so an employee unemployment claim does not affect this rate.

See the attached Related Link to the IRS Instructions for Form 940 (FUTA.)

See the Related Question below for information on Nevada.