One homeless man is still living in a city shelter even though he got a subsidy from the city eight months ago that would cover up to $1,246 a month for an apartment. Another woman has been moving from one family member to the next, despite having a similar subsidy for more than a year. And a homeless mother is forced to stay in a hotel in Queens with her two daughters, even though the city has promised to pay a landlord a year of her rent for leasing her an apartment.

Across the city, housing experts say landlords regularly reject applications from New Yorkers who receive housing subsidies despite a decade-old City Council law aimed to prevent the practice. And it is having an effect on homelessness. According to city statistics, more than 11,000 households are currently living in city shelters, even though they have vouchers that would cover their rent.

“We are contacted on a daily basis by people who've been denied over and over again,” said Katherine Carroll, an assistant commissioner at the city’s Commission on Human Rights, which enforces the 2008 law against source of income discrimination. “They're having to remain in shelters for months, if not years.”

Listen to Mirela Iverac’s reporting on WNYC:

In New York, landlords often require applicants to annually earn 40 times the monthly rent (or a similar multiple) as a way of ensuring their tenants are able to afford an apartment. But if applied to voucher holders, who are low-income, that policy excludes almost all of them. On average, households in city shelters that work earn less than $24,000 in a year. According to the 40 times rule, that’s only enough to cover a $600/month apartment, which is virtually impossible to find in the five boroughs.

Advocates say this is a new, more sophisticated way of violating the source of income law. In earlier years, violations were more blatant, such as landlords posting ads on Craigslist saying they don’t accept any programs.

“What we're seeing are neutral-sounding policies that in their design and the way they're applied actually exclude people almost as much as the rules that say don't even bother to apply if you have a program,” said Diane Houk, a tenant attorney.

After seeing more and more of these cases, advocates have opened a new front to fight discrimination against voucher holders. Houk represents a non-profit, the Fair Housing Justice Center, which is suing Pelican Management, Fordham One Company, and Cedar Two Company — property owners and managers with more than 6,000 apartments in the city and surrounding suburbs — in federal court. (An attorney for the property companies declined to comment for this story.) And the city’s Commission on Human Rights has filed a complaint against Parkchester, a housing complex with more than 12,000 units in the Bronx, alleging discrimination against people with subsidies.

If these lawsuits succeed, advocates say, they could send a message to other landlords who are rejecting voucher holders and help address the homelessness crisis. Armen Merjian, a senior staff attorney at Housing Works, says they would also tackle the kind of discrimination one of his former clients, who qualified for a voucher as a low-income person suffering from HIV/AIDS, faced, when he went to a realtor.

“They kept steering him to some of the worst apartments,” Merjian said.

The client then noticed nicer apartments renting within the range of his subsidy in the realtor’s window but was told some apartments are for him and some are for “regular people.”

“You're a person with a program, you’re poor, African American, living with HIV/AIDS. So, you're not a regular person,” Merjian said. “That tells us so much about why these folks [landlords] are discriminating. It revolves around race and class.”

Mirela Iverac is a reporter for WNYC, where she covers poverty and homelessness. You can follow her on Twitter at @mirelaiverac.