Many Rhode Island workers — and their employers — face sharp increases in payroll-related taxes next year.

Most Rhode Island workers will have to pay more into the state-run Temporary Disability Insurance (TDI) program.

And many employers will have to pay more into Rhode Island’s unemployment insurance fund, mainly because the balance in the state’s unemployment trust fund has plunged as unemployment has risen.

Figures for next year were posted late yesterday by the state Department of Labor and Training.

The maximum amount a worker pays in TDI tax will jump by 18.8 percent, to $840 next year from $707.20 this year.

The TDI tax has two key components: the tax rate, and the amount of wages to which that rate applies. Both are going up, starting Jan. 1.

The tax rate will be 1.5 percent, up from 1.3 percent for this year.

In addition, the amount of wages to which the tax rate applies will be $56,000, up from $54,400 this year.

The increase is the result, in part, of an increase in the average wages earned by Rhode Island workers, said agency spokeswoman Laura Hart.

“The average wage in Rhode Island went up, so [the tax] went up,” she said. An increase in TDI benefits also played a role in the tax hike, state figures show.

Because of the way the formula works, if a worker’s pay remains the same next year, the worker’s TDI tax will still increase.

Patricia A. Thompson, former president of the Rhode Island Society of Certified Public Accountants, said that the TDI tax increase represents “another demand on the taxpayer’s money that they have no control over.”

TDI is paid for through a tax levied on workers. TDI covers most people who work in Rhode Island, no matter where they live.

The program generally pays benefits to people who are temporarily out of work because of illness or injury unrelated to work.

Last year, about 422,000 workers contributed to the TDI fund, the state agency said. (Certain workers are not covered by TDI, including many government workers.)

Separately yesterday, the Department of Labor and Training announced an increase in the tax that many employers must pay into the state’s unemployment insurance program.

The increase is the result of a nearly 40-percent drop in the state’s unemployment trust fund, which helps to pay for benefits to people who lose their jobs.

The amount of reserves held in the trust fund was $116.8 million as of Sept. 30, down from $191.7 million at the same point last year, state figures show.

The decline is the result of higher unemployment, Hart said. (Rhode Island’s unemployment rate is 8.8 percent, the highest in the nation.) As unemployment rises, claims for benefits increase, reducing the amount held in the trust fund.

When that happens, the state agency increases the unemployment insurance tax — a tax paid entirely by employers — to replenish the fund, said Thompson, tax partner at Piccerelli Gilstein & Co. LLP, a CPA firm in Providence.

The amount of a worker’s wages to which the unemployment tax applies will jump to $18,000 next year from $14,000 this year, a 28.6-percent hike.

That means “the employer’s cost is going to go up,” Thompson said.

But how much of an increase each employer will have to bear will depend on the applicable tax rate; a different tax rate applies to each employer, she said.

For example, tax rates for next year will generally range from a minimum of 1.69 percent to a maximum of 9.79 percent, the same range that generally applies for this year.

Thompson offered the following example:

Suppose an employer has 10 workers, each making more than $18,000. Suppose, too, that the employer’s unemployment insurance tax rate is the maximum, at 9.79 percent.

Because there will be an increase next year in the amount of a worker’s wages to which that tax rate is applied, the employer in this example would face an overall increase of about $3,916 in state unemployment insurance tax next year, she said.

Employers will be notified next month of their individual tax rates for next year, the agency said. The rate for new employers has been reduced, to 2.36 percent for next year from 2.43 percent this year, the agency said.

About 35,000 employers pay into the state’s unemployment insurance trust fund, state figures show.

ndowning@projo.com