The present study deals with preparing a polymer-based material with incorporated ceramics and monitoring changes in properties after in vitro natural degradation. The developed material is a mixture of polymers of polylactic acid and polyhydroxybutyrate in a ratio of 85:15. Ceramic was incorporated into the prepared material, namely 10% hydroxyapatite and 10% tricalcium phosphate of the total volume. The material was processed into a filament form, and types of solid and porous samples were prepared using additive technology. These samples were immersed in three different solutions: physiological solution, phosphate-buffered saline, and Hanks’ solution. Under constant laboratory conditions, changes in solution pH, material absorption, weight loss, changes in mechanical properties, and surface morphology were monitored for 170 days. The average value of the absorption of the solid sample was 7.07%, and the absorption of the porous samples was recorded at 8.33%, which means a difference of 1.26%. The least change in pH from the reference value of 7.4 was noted with the phosphate-buffered saline solution. Computed tomography was used to determine the cross-section of the samples. The obtained data were used to calculate the mechanical properties of materials after degradation. The elasticity modulus for both the full and porous samples degraded in Hanks’ solution (524.53 ± 13.4 MPa) has the smallest deviation from the non-degraded reference sample (536.21 ± 22.69 MPa).