Yes. The income has parameters and your wages/salary must be within those parameters.
For example, a developer could build a block of apartments (using low-income tax credits from the government) and then rent these apartments to low-income families. Those families however must apply to go on a list, and provide evidence of their annual incomes and earnings in order to be eligible to rent one of these apartments. The decision who to rent to can vary, depending on who is on the list ahead of you (they will favor a family with children before a single or childless couple), and various other factors.
It is not a case of 100 apartments are built and each are rented to 100 families for $100, $200, $500, $600 per month - varying depending on the families income. No, the apartments are the same rent for everyone. The requirement is that the families have earnings of (let's say) $20,000 to $30,000 per annum. Then this would mean the family is eligible to apply for one of these apartments. If one family earns $20,000, they pay $200 per month in rent. If another family earns $28,000, they pay $200 per month also.
Ignore the numbers since I am using figures to show you examples only.
The only way to find out that information is to contact the leasing agent for the apartment building, or HUD, or whatever the government entity is that provides the low-income credits within the state you live.
See sample of HUD income limits for the State of Washington.