Versions of Iowa Code 147.140 - Expert witness -- certificate of merit affidavit on LawServer 2023 Iowa Code 147.140 – Expert witness — certificate of merit affidavit 2022 Iowa Code 147.140 – Expert witness — certificate of merit affidavit. 2020 Iowa Code 147.140 – Expert witness — certificate of merit affidavit. 2018 Iowa Code 147.140 – Expert witness — certificate of merit affidavit.