Factbox: Congress scrambles to wrap up 2011

(Reuters) - The Congress is scrambling to wrap up its work for the year and find elusive agreements on a number of issues affecting Americans' pocketbooks.

Here's a look at the to-do list facing the Democratic-led Senate and Republican-controlled House of Representatives while President Barack Obama seeks common ground:

PAYROLL TAX

Fearing a possible voter backlash in next year's elections, Democrats and Republicans are scrambling to find a deal to extend a popular payroll tax rate, set to expire on December 31.

If not renewed, a typical American family would see their taxes increase by about $1,000 next year. The key stumbling block is how to cover the cost, expected to hit $110 billion next year. Democrats favor a surtax on millionaires; Republicans want to extend a pay freeze on federal workers.

Democratic and Republican lawmakers skirmished on Friday over plans to extend the payroll tax cut seen as crucial to a fragile U.S. economic recovery, but aides predicted a last-minute deal. Senior party aides say they expect horse trading to begin in earnest next week.

JOBLESS BENEFITS

Federal unemployment insurance programs also are set to begin expiring at the end of this month, potentially affecting millions of Americans.

Democrats and Republicans are expected to renew them as part of an anticipated deal on the payroll tax cut. Part of the final deal could be easing proposed Republican tightening of eligibility requirements.

KEYSTONE XL PIPELINE

Republicans want to tie a renewal of the payroll tax break to their demands to accelerate approval of the proposed Keystone XL pipeline between the United States and Canada.

Obama and many of his Democrats say the pipeline, along with its environmental concerns, should be considered separately from the payroll tax.

But many pro-Democratic unions agree with Republicans that the project is urgently needed for job growth, raising Republicans hopes that the White House will go along with it.

GOVERNMENT FUNDING

House and Senate negotiators are expected to sign off next week on wrapping together in one massive measure nine funding bills for a variety of federal agencies, including defense, energy, homeland security, health, education, labor interior and foreign operations.

Congress has until Friday, December 16 to fund these agencies or face a partial government shutdown, which all sides would like to avoid given the fragile economy and widespread disdain for Congress.

A senior Republican aide said the regular discretionary total for fiscal 2012, when all spending bills are included, will total $1.043 trillion, down $7 billion from last year's levels.

"DOC FIX"

Congress faces another December 31 deadline for deciding whether to prevent a 27 percent pay cut for Medicare reimbursements to doctors.

Lawmakers repeatedly have avoided tackling a long-term fix for the reimbursement formula for Medicare, the increasingly expensive U.S. health program for those age 65 and older.

Instead, lawmakers typically have opted for short-term solutions. They are expected to do so again and may likely make it part of a sweeping deal to extend the payroll tax.

TEMPORARY TAX BREAKS

Congress may allow several tax breaks to expire at year's end, at least temporarily, as it pushes to increase revenues and decrease the record $15 trillion U.S. debt.

These expiring tax breaks include deductions for state and local sales taxes and college tuition as well as a research and development tax credit for businesses.

DEFENSE BILL

House and Senate negotiators are trying to resolve differences between their defense authorization bills, which contain provisions opposed by the Obama administration.

The Senate version, for example, would broaden the military's responsibility for holding terror suspects. The Senate bill would also impose new sanctions on the Central Bank of Iran. A similar measure has passed a House committee and may soon be considered by the full House.

The administration doesn't like the proposed sanctions, saying it prefers to work in a calibrated manner to avoid roiling oil markets or antagonizing allies.

(Reporting by Thomas Ferraro, Roberta Rampton, Donna Smith, Richard Cowan, Susan Cornwell; editing by Anthony Boadle)