The Seimas approved the structure on Thursday with 114 votes in favor, none against and no abstentions.
The document sets the threshold number of servicemen and servicewoman for 2019 at between 19,490 and 22,450, up to 500 more than this year.
It is planned to increase the overall threshold number by 5,500 within six years to between 24,390 and 26,850 people.
Between 3,800 and 4,000 young men are to be conscripted to mandatory initial military service in 2019, unchanged from this year.
However, the number of senior officers in the Armed Forces is set to increase next year. According to Defense Minister Raimundas Karoblis, the number of lieutenant colonels is to grow by 13 to 220 and the number of majors is to rise by 107 to 780 people.
The document also provides for establishing a communications and IT battalion.
A logistics battalion is to be set up by 2024.