8.54% of the population for whom poverty status is determined in Mountain Lake, NJ (49 out of 574 people) live below the poverty line, a number that is lower than the national average of 12.5%. The largest demographic living in poverty are Males 45 - 54, followed by Females 45 - 54 and then Males 25 - 34.

The most common racial or ethnic group living below the poverty line in Mountain Lake, NJ is White, followed by Black and Native American.

The Census Bureau uses a set of money income thresholds that vary by family size and composition to determine who classifies as impoverished. If a family's total income is less than the family's threshold than that family and every individual in it is considered to be living in poverty.