Nytavia Ragsdale, 26, and Laron Modlin, 25, were originally charged with manslaughter and endangering the welfare of a child.
The Manhattan District Attorney's Office added murder in the second degree.
Authorities said the parents cut off access to food in their home for their four kids for 2 years while purchasing food for themselves on a daily basis.
Court documents said the apartment had a working refrigerator that contained fresh produce but was turned so that the door was facing the wall and could not be opened.
Court documents also said any cabinet containing food had a zip tie on the handle.
Jah'Meik Modlin weighed 19 pounds when he died.
Officials said Jah'Meik and his siblings arrived at the hospital with layers of dirt on their skin and feces matted in their hair.
Officials said his three siblings, who remain hospitalized for malnutrition, displayed very limited fine motor skills and were incapable of holding any utensils or of feeding themselves.
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