The doctrines Iowa courts name when they cite: mined from the sentence each citation lives in, keyed on the citing court, counted by distinct opinions. Entry by issue, not by case: pick one to see the cases on each side.
| # | Issue | Most-cited case | Opinions | Courts | Years | Last 5y |
|---|---|---|---|---|---|---|
| 1 | fundamental doctrine | Meier v. SENECAUT III | 977 | 2 | 1879–2026 | 330 |
| 2 | appellate review that issues must ordinarily doctrine | Meier v. SENECAUT III | 705 | 2 | 2002–2026 | 296 |
| 3 | time of the termination hearing | In The Interest Of D.W., Minor Child, A.M.W., Mother | 655 | 2 | 1989–2026 | 332 |
| 4 | ineffective assistance of counsel claim | Strickland v. Washington | 601 | 2 | 1980–2026 | 96 |
| 5 | due process clause | State v. Graves | 555 | 2 | 1932–2026 | 87 |
| 6 | ineffective assistance claim | State v. Straw | 397 | 2 | 1984–2026 | 47 |
| 7 | affirmative defense | State v. Delay | 331 | 2 | 1895–2026 | 39 |
| 8 | warrant requirement | State of Iowa v. Jesse Michael Gaskins | 291 | 2 | 1940–2026 | 61 |
| 9 | best-interest framework | In Re P.L. | 253 | 2 | 2010–2026 | 86 |
| 10 | hearsay rule | State v. Long | 242 | 2 | 1915–2025 | 37 |
| 11 | equal protection clause | Varnum v. Brien | 240 | 2 | 1930–2025 | 25 |
| 12 | Miranda warning | Miranda v. Arizona | 211 | 2 | 1968–2026 | 34 |
| 13 | reputation bar | IA S. CT. ATTY. DISCIPLINARY BD. v. Ireland | 202 | 1 | 1985–2026 | 15 |
| 14 | abuse of discretion standard | State v. Formaro | 200 | 2 | 1947–2026 | 41 |
| 15 | exclusionary rule | State v. Cline | 195 | 2 | 1941–2025 | 31 |
| 16 | Iowa rule | Squealer Feeds v. Pickering | 193 | 2 | 1902–2026 | 9 |
| 17 | weight of the evidence standard | State v. Reeves | 189 | 2 | 2001–2026 | 65 |
| 18 | sufficiency of the evidence standard | State v. Nitcher | 187 | 2 | 1984–2026 | 64 |
| 19 | rational basis test | Racing Ass'n of Central Iowa v. Fitzgerald | 185 | 2 | 1977–2026 | 24 |
| 20 | Alford plea | North Carolina v. Alford | 182 | 2 | 1979–2026 | 41 |
| 21 | correction of legal error | State v. Banes | 140 | 2 | 1990–2026 | 41 |
| 22 | ethical violation | Iowa Supreme Court Attorney Disciplinary Board v. James C. Van Ginkel | 137 | 2 | 1983–2026 | 8 |
| 23 | reasonable efforts requirement | In Re CB | 134 | 2 | 2014–2026 | 63 |
| 24 | statutory best interest framework | In Re P.L. | 131 | 2 | 2010–2026 | 28 |
| 25 | Strickland test | State of Iowa v. Allen Bradley Clay | 129 | 2 | 1987–2026 | 25 |
| 26 | harmless error | State v. Sullivan | 121 | 2 | 1971–2026 | 27 |
| 27 | district court fails rule | Meier v. SENECAUT III | 119 | 2 | 2003–2026 | 42 |
| 28 | ease bar | State v. De Koning | 115 | 2 | 1879–2006 | 0 |
| 29 | issue may be deemed waiver | Hyler v. Garner | 110 | 2 | 1980–2025 | 38 |
| 30 | best-interests analysis | In the Interest of H.S. And S.N., Minor Children, V.R., Mother | 108 | 2 | 2013–2026 | 76 |
| 31 | per se rule | State v. Straw | 103 | 2 | 1976–2025 | 12 |
| 32 | prima facie violation | Duren v. Missouri | 100 | 2 | 1865–2026 | 28 |
| 33 | Fifth Amendment privilege | Miranda v. Arizona | 99 | 2 | 1966–2026 | 13 |
| 34 | preponderance standard | Iowa Supreme Court Board of Professional Ethics & Conduct v. Lett | 99 | 2 | 1980–2025 | 3 |
| 35 | Fourth Amendment violation | Whren v. United States | 97 | 2 | 1969–2026 | 18 |
| 36 | confrontation clause | Crawford v. Washington | 96 | 2 | 1971–2026 | 18 |
| 37 | parol evidence rule | Hamilton v. Wosepka | 96 | 2 | 1916–2025 | 5 |
| 38 | PCR hearing | Harrington v. State | 95 | 2 | 2001–2026 | 43 |
| 39 | qualified privilege | Barreca v. Nickolas | 92 | 2 | 1899–2026 | 17 |
| 40 | Brady violation | David R. Desimone v. State of Iowa | 87 | 2 | 1977–2026 | 27 |
| 41 | good faith exception | State v. Cline | 85 | 2 | 1900–2025 | 12 |
| 42 | double jeopardy clause | State v. McKettrick | 82 | 2 | 1973–2026 | 4 |
| 43 | reasonable doubt error | Chapman v. California | 81 | 2 | 1878–2024 | 4 |
| 44 | permissive exception | In the Interest of M.W. and Z.W., Minor Children, R.W., Mother | 80 | 2 | 1984–2026 | 61 |
| 45 | compliance standard | State of Iowa v. Kevin Duane Fisher II | 79 | 2 | 1885–2025 | 12 |
| 46 | mootness doctrine | Amended July 30, 2015 Danny Homan, Steven J. Sodders, Jack Hatch, Pat Murphy, and Mark Smith v. Terry Branstad, Governor, State of Iowa, and Charles M. Palmer, Director, Iowa Department of Human Services | 78 | 2 | 1982–2025 | 20 |
| 47 | categorical rule | State of Iowa v. Charles James David Oliver | 76 | 2 | 1996–2025 | 19 |
| 48 | Sixth Amendment violation | Strickland v. Washington | 76 | 2 | 1980–2025 | 12 |
| 49 | uniform instruction | Comes v. Microsoft Corp. | 74 | 2 | 1862–2026 | 7 |
| 50 | potential viability claim | State v. Johnson | 71 | 2 | 2006–2020 | 0 |
| 51 | statute of limitations defense | Harrington v. State | 71 | 2 | 1880–2026 | 12 |
| 52 | exhaustion requirement | Rowen v. LeMars Mutual Insurance Co. of Iowa | 70 | 2 | 1972–2026 | 9 |
| 53 | guilty plea hearing | State v. Schminkey | 68 | 2 | 1975–2024 | 9 |
| 54 | parent challenge | In Re P.L. | 67 | 2 | 1955–2026 | 48 |
| 55 | first prong test | Strickland v. Washington | 65 | 2 | 1983–2024 | 1 |
| 56 | marshalling instruction | Strickland v. Washington | 65 | 2 | 1974–2025 | 12 |
| 57 | structural error | Daniel Lado v. State of Iowa | 65 | 2 | 2003–2026 | 21 |
| 58 | marshaling instruction | State v. Propps | 64 | 2 | 1898–2026 | 22 |
| 59 | permanency or termination hearing | In Re AAG | 64 | 1 | 2005–2026 | 12 |
| 60 | statutory best-interests framework | In Re P.L. | 64 | 1 | 2014–2025 | 3 |
| 61 | law of the case doctrine | State of Iowa v. Jeffrey K. Ragland | 63 | 2 | 1945–2026 | 10 |
| 62 | Terry stop | Terry v. Ohio | 63 | 2 | 1984–2026 | 17 |
| 63 | cruel and unusual punishment clause | State v. Lyle | 62 | 2 | 2009–2025 | 4 |
| 64 | felony-murder rule | State v. Heemstra | 62 | 2 | 1975–2025 | 7 |
| 65 | ineffective-assistance-of-trial-counsel claim | Brian K. Allison v. State of iowa | 62 | 2 | 2015–2023 | 38 |
| 66 | speedy indictment rule | State Of Iowa Vs. Jason Allen Wing | 62 | 2 | 1980–2025 | 9 |
| 67 | demanding standard | Alabama v. White | 61 | 2 | 1979–2026 | 11 |
| 68 | attorney violated rule | Iowa Supreme Court Attorney Disciplinary Board v. Richard Scott Rhinehart | 60 | 2 | 2011–2025 | 8 |
| 69 | plain error | State of Iowa v. Mark Gabriel Martin | 60 | 2 | 1880–2025 | 21 |
| 70 | res ipsa loquitur doctrine | Wiles v. Myerly | 60 | 2 | 1923–2025 | 5 |
| 71 | substantive due process challenge | Rozanne E. King Alisha Jane King Dacie S. Houston, Individually and as Mother and Next Friend of Skylar Dwayne Ostrander, Chay Cortez Ostrander, and Adlia William Cortez Flood III Brandy R. Drake, Individually and as Mother and Next Friend of Logan Genner Luhmann, Susan Maule, Stephanie Maule, and Jacob Maule Michael Campbell, Individually and as Father and Next Friend of George Campbell and Soph | 60 | 2 | 1983–2024 | 7 |
| 72 | agency rule | Milholin v. Vorhies | 59 | 2 | 1923–2023 | 2 |
| 73 | automobile exception | State of Iowa v. Christopher George Storm | 59 | 2 | 1979–2026 | 17 |
| 74 | speedy trial rule | State v. Miller | 59 | 2 | 1971–2026 | 8 |
| 75 | second step analysis | In The Interest Of D.W., Minor Child, A.M.W., Mother | 58 | 2 | 1988–2026 | 14 |
| 76 | burden to establish exception | In the Interest of A.M., Minor Child, A.M., Father | 56 | 2 | 1933–2025 | 26 |
| 77 | colorable future claim | Iowa Supreme Court Attorney Disciplinary Board v. John Michael Carter | 56 | 2 | 2004–2025 | 3 |
| 78 | ruling error | State v. Tillman | 56 | 2 | 1879–2026 | 14 |
| 79 | elementary rule | Miller v. Marshall County | 55 | 2 | 1863–2023 | 4 |
| 80 | framework analysis | In Re the Marriage of Kleist | 55 | 2 | 1990–2023 | 9 |
| 81 | Miller factors | State v. Lyle | 55 | 2 | 1964–2025 | 12 |
| 82 | Mother challenge | In Re P.L. | 55 | 1 | 2015–2026 | 21 |
| 83 | separation of powers doctrine | Klouda v. Sixth Judicial District Department of Correctional Services | 55 | 2 | 1976–2026 | 11 |
| 84 | face error | DeVoss v. State | 54 | 2 | 1939–2026 | 16 |
| 85 | law of appeal error | State v. Rutledge | 54 | 2 | 2014–2026 | 30 |
| 86 | probable cause standard | Children v. Burton | 54 | 2 | 1978–2026 | 19 |
| 87 | assigned error | State v. Niccum | 53 | 1 | 1864–1986 | 0 |
| 88 | error preservation rule | State of Iowa v. Andre Letroy Antwan Harrington | 53 | 2 | 1997–2025 | 14 |
| 89 | first step analysis | In Re P.L. | 53 | 2 | 1983–2024 | 13 |
| 90 | merger doctrine | State v. Heemstra | 53 | 2 | 1883–2026 | 3 |
| 91 | legal elements test | State v. Halliburton | 52 | 2 | 1976–2026 | 15 |
| 92 | scrutiny analysis | Sanchez v. State | 52 | 2 | 1980–2026 | 8 |
| 93 | vagueness challenge | Knight v. IOWA DIST. COURT OF STORY CTY. | 52 | 2 | 1976–2024 | 3 |
| 94 | individualized sentencing hearing | State v. Lyle | 50 | 2 | 2013–2025 | 9 |
| 95 | public policy exception | Springer v. Weeks and Leo Co., Inc. | 50 | 2 | 1964–2025 | 7 |
| 96 | search and seizure clause | State of Iowa v. Tommy Tyler, Jr. | 50 | 2 | 2005–2025 | 17 |
| 97 | state constitutional claim | State of Iowa v. Stephen Scott Prusha | 50 | 2 | 1995–2026 | 5 |
| 98 | discretionary standard | State v. Wright | 49 | 2 | 2005–2026 | 39 |
| 99 | justification defense | State v. Carey | 49 | 2 | 1979–2026 | 11 |
| 100 | meritless claim | State of Iowa v. Robin Eugene Brubaker | 49 | 2 | 2004–2025 | 8 |
| 101 | sovereign immunity | Lloyd v. State | 49 | 2 | 1969–2025 | 8 |
| 102 | causation standard | Teachout v. Forest City Community School District | 48 | 2 | 1982–2023 | 7 |
| 103 | good cause standard | Sharece Rucker v. Mike Taylor and Sherie Taylor | 48 | 2 | 1975–2026 | 21 |
| 104 | permanency hearing | In Re AAG | 48 | 2 | 1989–2026 | 22 |
| 105 | attorney performed below standard | Ledezma v. State | 47 | 2 | 2001–2026 | 14 |
| 106 | explicit standard | State v. Pierce | 47 | 2 | 1873–2024 | 5 |
| 107 | physician-patient privilege | State v. Bedel | 47 | 2 | 1969–2023 | 1 |
| 108 | postconviction relief hearing | State v. Straw | 47 | 2 | 1997–2026 | 9 |
| 109 | exigent circumstances exception | State of Iowa v. Christopher George Storm | 46 | 2 | 1977–2025 | 14 |
| 110 | operation rule | Windus v. Great Plains Gas | 46 | 2 | 1864–2018 | 0 |
| 111 | totality of the circumstances test | State of Iowa v. Kenneth Lee Madsen | 46 | 2 | 1970–2025 | 11 |
| 112 | individualized hearing | State v. Lyle | 45 | 2 | 1995–2025 | 4 |
| 113 | purposes rule | State v. Mann | 45 | 2 | 1928–2025 | 13 |
| 114 | res judicata doctrine | Spiker v. Spiker | 45 | 2 | 1906–2026 | 4 |
| 115 | nonconstitutional error | State v. Sullivan | 44 | 2 | 2004–2026 | 13 |
| 116 | related claim | Summy v. City of Des Moines | 43 | 2 | 1964–2021 | 1 |
| 117 | community caretaking exception | Cady v. Dombrowski | 42 | 2 | 2012–2026 | 14 |
| 118 | fair cross-section requirement | Duren v. Missouri | 42 | 2 | 1989–2025 | 20 |
| 119 | issue preclusion doctrine | Hunter v. City of Des Moines | 42 | 2 | 1977–2026 | 5 |
| 120 | bench bar | United States v. William Stewart McDowell | 41 | 2 | 1915–2026 | 3 |
| 121 | concepts waiver | State v. Ohnmacht | 41 | 2 | 1982–2026 | 9 |
| 122 | modern standard | Beedy v. Finney | 41 | 2 | 1871–2021 | 1 |
| 123 | ex post facto clause | State v. Lathrop | 40 | 2 | 1979–2025 | 4 |
| 124 | Iowa Administrative Code rule | Renda v. Iowa Civil Rights Commission | 40 | 2 | 1993–2026 | 10 |
| 125 | attorney-client privilege | Robbins v. IOWA-ILLINOIS GAS AND ELECTRIC COMPANY | 39 | 2 | 1969–2024 | 3 |
| 126 | excited utterance exception | State v. Atwood | 39 | 2 | 1978–2024 | 10 |
| 127 | precise test | Jacobson Transportation Co. v. Harris | 39 | 2 | 1877–2026 | 4 |
| 128 | necessity defense | State v. Walton | 38 | 2 | 1862–2025 | 7 |
| 129 | bad faith claim | Bellville v. Farm Bureau Mutual Insurance Co. | 37 | 2 | 1965–2026 | 4 |
| 130 | discretionary function exception | Berkovitz v. United States | 37 | 2 | 1977–2025 | 5 |
| 131 | federal constitutional claim | Racing Ass'n of Central Iowa v. Fitzgerald | 37 | 2 | 1974–2023 | 4 |
| 132 | interpretation rule | State v. Jordan | 37 | 2 | 1941–2024 | 4 |
| 133 | limitations defense | Harrington v. State | 37 | 2 | 1904–2026 | 4 |
| 134 | right to assert error | State v. Taggart | 37 | 2 | 1910–2025 | 6 |
| 135 | Batson challenge | Batson v. Kentucky | 36 | 2 | 1989–2026 | 16 |
| 136 | like rule | In Re Eickman Estate | 36 | 2 | 1849–1997 | 0 |
| 137 | relation-back doctrine | Brian K. Allison v. State of iowa | 36 | 2 | 1992–2026 | 22 |
| 138 | standing requirement | State v. Robinson | 36 | 2 | 1972–2025 | 7 |
| 139 | attorney violates rule | Iowa Supreme Court Attorney Disciplinary Board v. Richard Scott Rhinehart | 35 | 1 | 2013–2025 | 4 |
| 140 | case falls within rule | Green v. Advance Homes, Inc. | 35 | 2 | 1864–2019 | 0 |
| 141 | commerce clause | Complete Auto Transit, Inc. v. Brady | 35 | 1 | 1882–2015 | 0 |
| 142 | de novo standard | In Re Estate of Warrington | 35 | 2 | 1974–2026 | 7 |
| 143 | development of the ineffective-assistance claim | State of Iowa v. Anthony Antoine Harris | 35 | 2 | 2018–2021 | 2 |
| 144 | estoppel doctrine | Helwig v. Fogelsong | 35 | 2 | 1864–2024 | 3 |
| 145 | alibi instruction | State v. Stump | 34 | 2 | 1911–2023 | 2 |
| 146 | burden of proving violation | Iowa Supreme Court Attorney Disciplinary Board v. James C. Van Ginkel | 34 | 2 | 1902–2025 | 6 |
| 147 | consent exception | State v. McLees | 34 | 2 | 1888–2026 | 8 |
| 148 | emergency aid doctrine | State v. Crawford | 34 | 2 | 1996–2025 | 5 |
| 149 | Father challenge | In Re P.L. | 34 | 2 | 2009–2026 | 14 |
| 150 | granting clause | McCleary v. Ellis | 34 | 2 | 1893–2019 | 0 |
Top 150 by distinct citing opinions.