Justin Streicher, 25, pleaded no contest in February to neglecting a child, causing death in the girl's death, the Milwaukee Journal Sentinel reported.
The girl's mother, Leann L. Leszynski, 26, faced the same charges and entered the same plea. She was also sentenced to 15 years in prison.
Both Streicher and Leszynski were ordered to serve 10 years of extended supervision following their release from prison.
Leszynski's daughter, Haley Kluwe, died May 1, 2012, of a massive streptococcus infection throughout her body.
Officials said Leszynski and Streicher didn't call 911 or seek emergency medical help after discovering Haley's body. The couple did, however, ask Leszynski's mother to take care of Haley's twin sister and older sister.
Later, Leszynski admitted to her physician that the girl was dead and the doctor's office called police.
During a search of Streicher and Leszynski's apartment, police said they found heroin, oxycodone, cocaine and marijuana.