7 Pa. Code § 137b.83
If enrolled land undergoes split-off and the tract that is split-off meets the size, use and aggregate acreage requirements in section 6(a.1)(1)(i) of the act (72 P. S. § 5490.6(a.1)(1)(i)), the landowner who conducted the split-off shall owe roll-back taxes and interest with respect to the split-off tract. The preferential assessment of that split-off tract shall be terminated. If the remainder of the enrolled land is in agricultural use, agricultural reserve or forest reserve, and continues to meet the requirements of section 3 of the act (72 P. S. § 5490.3), no roll-back taxes are due with respect to that remainder, and preferential assessment shall continue with respect to that tract.
Example: Landowner owns 50 acres of enrolled land. Landowner splits off 2 acres for a residential dwelling, in compliance with section 6(a.1)(1)(i) of the act. The landowner owes roll-back taxes and interest on the 2-acre tract, and the preferential assessment of that tract shall be terminated. The remaining 48-acre tract would continue to receive preferential assessment, assuming it remains in agricultural use, agricultural reserve or forest reserve and otherwise continues to meet the requirements of section 3 of the act (72 P. S. § 5490.3).
7 Pa. Code § 137b.83