The Diploma Education (DepEd) teacher performance measures must meet specific critical objectives. DepEd Order 42 (2017), requires seven domains and thirty-seven strands for teachers’ development. The criteria helps teachers learn. A teacher career’s advancement depends on performance. The Philippine Professional Standards for Teachers (PPST) aims to deliver quality basic education. Teachers planning domain-performance indicators teaching abilities include structuring progressive learning to meet course goals. Some teachers avoid the professional way of developing lesson ideas. This causes a “bandwagon effect” of teachers ignoring lesson planning and assigning repetitive tasks. The study worked on an indicator-based lesson plan evaluation method for science teachers. A weekly lesson plan (LP) monitoring tool was scheduled (WLPMT). The WLPMT evaluated the learning plans. The study applied quantitative research techniques. Excel’s statistical analysis tool analyzed the data. The researchers employed a contextualized developmental monitoring and assessment instrument for lesson plans, which included teacher lesson plan rate indicators. The goal of this study is to enhance science teachers instructional planning. The evaluated null hypothesis was not substantially different, the two-tailed t-test t value (0.67) was lower than the critical value (2.26) in the 1st (78.1, 9.30) and 2nd (81, 20.41) quarters. Their SD was higher than the 1st quarter, despite their higher mean score differential for the 2nd quarter. However, the results showed that the teacher’s instructional planning skills were still improving. The computed t-test for the 1st (78.1, 9.30) and 3rd (89.5, 9.10) quarters show a significant mean difference because the t value (4.45) exceeds the critical value (2.26). In the third quarter, teachers utilized lesson planning indicators to improve instructional planning. In the fourth quarter (86.4, 12.22), mean scores exceeded baseline. The 4th quarter has a bigger standard deviation than the 1st quarter, yet the t test statistics exceeds the critical point, indicating a large mean score difference. The study concluded that teachers who produce quality instructional plans may benefit from lesson plan scores.