Frederick Nevins, 51, a planning official with the Maryland Department of Health and Mental Hygiene, died Friday at Easton Memorial Hospital in Easton, Md., following a heart attack. A Rockville resident, he had gone to Easton on business when he was stricken.

Dr. Nevins joined his state health department in 1968 after a 20-year career in the U.S. Public Health Service, from which he retired with the rank of captain. He was associate executive director of the health planning and development agency in the Maryland department at the time of his death.

A native of New York City, Dr. Nevins was a graduate of the City College of New York. He earned a master's degree at New York University and a doctorate in public administration at the University of Pittsburgh.

He joined the PHS in New York as a chemical engineer in 1948. He was transferred to Washington in 1957 and was involved in health planning and management until he retired.

Dr. Nevins belonged to the American Public Health Associaton. A member of Washington Hebrew Congregation, he was on its long-range planning committee.

Survivors include his wife, Joan, of the home, two sons, David and Eric, both of Baltimore, and a daughter, Lizabeth, of the home.