FACTBOX: How do U.S. healthcare proposals compare?

(Reuters) - U.S. lawmakers returned from a weeklong break on Monday to face what could be the year's most severe test -- finding common ground on a huge, costly healthcare overhaul.

Lawmakers in Congress are working on several draft versions of proposals to meet President Barack Obama's top legislative priority of overhauling the U.S. healthcare system.

In the House of Representatives, three committees have joined together to produce one draft House bill.

In the Senate, the Health, Education, Labor and Pensions (HELP) Committee has started work on a second Democratic proposal, while the Senate Finance Committee is in closed-door negotiations over a possible third healthcare bill that would win bipartisan support.

Here is a summary comparing the various bills.

INSURANCE MARKET REFORMS

* The House and Senate bills all call for sweeping insurance market reforms.

* The House bill would set up a new government plan to compete with private companies. The Senate HELP panel bill leaves this open for later consideration.

* The Senate Finance Committee, chiefly to address Republican concerns, is instead looking at creating non-profit medical co-operatives to compete with insurers.