To some extent - this question is a debate among Lithuanian historians and one with no clear answer, partially due to a lack of sources, partially because of the unique circumstances in which Lithuania developed during the medieval period.

Medieval Lithuania, both Christian and pagan, never developed key features of Western feudalism - land organization based on fiefs and feudal contract to grant vassals hereditary ownership of land, and an enshrined social hierarchy of nobles, priesthood, and commoners. There's little to discuss about religious hierarchy since we know little to nothing about pagan Lithuanian religion, if it had a hierarchy and a supreme leader at all, and the existence of nobility is hard to pinpoint.

Early Medieval Lithuania was patrimonial - there were no fiefs, there were communities and villages who recognized the rule of the duke and the duke subsequently maintained his control by travelling from community to community with a warband, kariauna, receiving tribute and feasts from visited lands while using his authority to resolve any issues which the commoners bring up. More or less the same system was in place in the Slavic lands around this time, and in the Germanic tribes at the Early Feudal period.

In the late 13th and early 14th centuries, the realities of the war against the Teutonic Knights led to the formation of a different organization, based around pilėnai - garrisons. The Grand Duchy needed to maintain a series of castles to defend their territory from Teutonic raids and replenish their army for wars, so the garrisons of these castles were being granted rights, allodial land ownership and the right to collect tribute from surrounding territory in place of the Grand Duke. The same period also saw the formation of leičiai - a famous Lithuanian social class which answered directly to the monarch and was responsible for consolidating his rule in the Duchy's vast territory. They received land in the periphery and conquered Russian territory, established themselves as independent soldier-peasants and were required to answer the call to war and do service in the Grand Duke's holdings, mainly looking after horses and providing supplies.

This was closer to feudalism, but distinctly Early Medieval in appearance rather than anything like the West in the 14th century. Land was granted for service and rarely inherited, the peasantry were still free subjects, et cetera, et cetera.

Lithuania became Catholic in 1387, and while this is beyond the scope of the question, it was still an interesting period regarding social structure and its history. The years after, particularly the rule of Vytautas, were a crash transition towards feudalism. Lithuania rapidly adopted feudal privileges and legal systems, and Vytautas specifically hastened it, as he aimed to form a core of modern knights to support his ambitions and Lithuania's social system at the time wasn't sufficient. He rapidly handed out fiefs of land with indentured peasants, veldamai, to his supporters and former pilėnai and leičiai, granted them noble titles, and made military service for these newly crafted nobles mandatory. There are those who argue that Vytautas effectively created the Lithuanian nobility from scratch, and it has truth in it, though it is quite a reductionist view.

Even then, however, it's a debate on whether this truly shaped into full-on feudalism. By the early 16th century, when social hierarchy between nobility and serfs was firmly established, the largest magnates had already transitioned towards folwarks (large agrarian estates focused on production and profit), which is generally considered post-feudal.