The Treasury Department said Wednesday that the Obama Administration’s $50 billion mortgage relief program is beginning to reach troubled homeowners in greater numbers.

The program has been criticized for not reaching enough people who need it.

According to testimony at a Congressional hearing, nearly one in five eligible homeowners has been offered help so far. That’s a 4% increase from a month ago.

And more lenders have gotten on board as the program has expanded, according to the Treasury.

“There are signs the plan is working,” said Michael Barr, assistant Treasury secretary for financial institutions. “But we can do better.”

The “Making Home Affordable” plan got off to a slow start after its highly public launch in March. But Treasury officials say that’s changing. More than 571,000 loan modification offers, or 19%, have been sent to nearly three million eligible homeowners. That's up from 15% at the end of July.

Of those, more than 360,000 borrowers have signed up for three-month trial modifications, which are supposed to be extended for five years if the homeowners make their payments on time.

Treasury said 48 mortgage companies are now involved in the program, up from 38 in July. The companies have requested financial information from almost two-thirds of eligible borrowers and say they are on track to have 500,000 loan modifications in place by Nov. 1.

Some large lenders, such as Citigroup (C), have put in place their own loan modification programs.

Despite the new figures released Wednesday, lawmakers expressed frustration with the government program, especially as foreclosures continue to surge.

“I am disappointed at the pace of this program,” said Rep. Barney Frank (D-Mass.), chairman of the House Financial Services Committee.

While lenders say they are adding thousands of workers to modify loans, housing advocates say getting approved is still a time-consuming, bureaucratic nightmare. Many borrowers are also wary of signing up because they are worried their payment will rise after the three-month trial period is over.

The program is voluntary, relying on subsidies to encourage mortgage companies to participate. Lenders must agree to reduce the loan payments to 38% of a borrower's monthly income. After that, the government and lender split the cost of bringing the payment down to 31%.

Eligible borrowers have to provide their most recent tax return and two pay stubs, as well as an “affidavit of financial hardship” to qualify.