diff --git a/CMakeLists.txt b/CMakeLists.txt
index e86164a..1c31d3a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,7 @@ include(cmake/FesaDependencies.cmake)
 
 add_library(fesa_core STATIC
     src/fesa/core/version.cpp
+    src/fesa/io/abaqus/parser.cpp
     src/fesa/model/domain.cpp
     src/fesa/model/domain_builder.cpp
 )
diff --git a/include/fesa/io/abaqus/deck_record.hpp b/include/fesa/io/abaqus/deck_record.hpp
new file mode 100644
index 0000000..d685f3d
--- /dev/null
+++ b/include/fesa/io/abaqus/deck_record.hpp
@@ -0,0 +1,46 @@
+#pragma once
+
+#include <functional>
+#include <map>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include <fesa/core/source_location.hpp>
+
+namespace fesa {
+
+struct DeckRecord final {
+    std::string keyword;
+    std::map<std::string, std::string, std::less<>> parameters;
+    std::vector<std::vector<std::string>> data;
+    SourceLocation source;
+};
+
+struct ParsedPart final {
+    std::string name;
+    std::vector<DeckRecord> records;
+    SourceLocation source;
+};
+
+struct ParsedInstance final {
+    std::string name;
+    std::string part_name;
+    std::vector<std::vector<std::string>> transform_data;
+    SourceLocation source;
+};
+
+struct ParsedAssembly final {
+    std::string name;
+    std::vector<ParsedInstance> instances;
+    std::vector<DeckRecord> records;
+    SourceLocation source;
+};
+
+struct ParsedDeck final {
+    std::vector<DeckRecord> global_records;
+    std::vector<ParsedPart> parts;
+    std::optional<ParsedAssembly> assembly;
+};
+
+}  // namespace fesa
diff --git a/include/fesa/io/abaqus/parser.hpp b/include/fesa/io/abaqus/parser.hpp
new file mode 100644
index 0000000..29a9fa4
--- /dev/null
+++ b/include/fesa/io/abaqus/parser.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <filesystem>
+#include <optional>
+#include <vector>
+
+#include <fesa/core/diagnostic.hpp>
+#include <fesa/io/abaqus/deck_record.hpp>
+
+namespace fesa {
+
+struct ParseDeckResult final {
+    std::optional<ParsedDeck> deck;
+    std::vector<Diagnostic> diagnostics;
+};
+
+[[nodiscard]] ParseDeckResult parse_deck(
+    const std::filesystem::path& path);
+
+}  // namespace fesa
diff --git a/phases/index.json b/phases/index.json
index 2f65cf4..b72bee6 100644
--- a/phases/index.json
+++ b/phases/index.json
@@ -42,4 +42,4 @@
       "status": "pending"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/src/fesa/io/abaqus/parser.cpp b/src/fesa/io/abaqus/parser.cpp
new file mode 100644
index 0000000..55b2c53
--- /dev/null
+++ b/src/fesa/io/abaqus/parser.cpp
@@ -0,0 +1,411 @@
+#include <fesa/io/abaqus/parser.hpp>
+
+#include <algorithm>
+#include <array>
+#include <cstddef>
+#include <fstream>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
+
+namespace fesa {
+namespace {
+
+enum class Scope { global, part, assembly, instance };
+
+struct KeywordLine final {
+    std::string keyword;
+    std::map<std::string, std::string, std::less<>> parameters;
+    SourceLocation source;
+};
+
+std::string_view trim(const std::string_view value) {
+    constexpr std::string_view whitespace{" \t\f\v\r\n"};
+    const std::size_t first = value.find_first_not_of(whitespace);
+    if (first == std::string_view::npos) {
+        return {};
+    }
+    const std::size_t last = value.find_last_not_of(whitespace);
+    return value.substr(first, last - first + 1);
+}
+
+std::string uppercase_ascii(std::string value) {
+    std::ranges::transform(value, value.begin(), [](const char character) {
+        if (character >= 'a' && character <= 'z') {
+            return static_cast<char>(character - 'a' + 'A');
+        }
+        return character;
+    });
+    return value;
+}
+
+std::vector<std::string> split_fields(const std::string_view value) {
+    std::vector<std::string> fields;
+    std::size_t first = 0;
+    while (true) {
+        const std::size_t comma = value.find(',', first);
+        const std::string_view field = comma == std::string_view::npos
+                                           ? value.substr(first)
+                                           : value.substr(first, comma - first);
+        fields.emplace_back(trim(field));
+        if (comma == std::string_view::npos) {
+            break;
+        }
+        first = comma + 1;
+    }
+    return fields;
+}
+
+ParseDeckResult failure(
+    const DiagnosticStage stage,
+    std::string code,
+    std::string message,
+    std::optional<SourceLocation> source) {
+    std::vector<Diagnostic> diagnostics;
+    diagnostics.push_back({
+        stage,
+        Severity::error,
+        std::move(code),
+        std::move(message),
+        std::move(source),
+    });
+    return {std::nullopt, std::move(diagnostics)};
+}
+
+ParseDeckResult syntax_failure(
+    std::string code,
+    std::string message,
+    SourceLocation source) {
+    return failure(
+        DiagnosticStage::syntax,
+        std::move(code),
+        std::move(message),
+        std::move(source));
+}
+
+bool is_supported_record(const std::string_view keyword) {
+    constexpr std::array supported{
+        std::string_view{"BEAM GENERAL SECTION"},
+        std::string_view{"BOUNDARY"},
+        std::string_view{"CLOAD"},
+        std::string_view{"ELASTIC"},
+        std::string_view{"ELEMENT"},
+        std::string_view{"ELSET"},
+        std::string_view{"END STEP"},
+        std::string_view{"MATERIAL"},
+        std::string_view{"NODE"},
+        std::string_view{"NSET"},
+        std::string_view{"STATIC"},
+        std::string_view{"STEP"},
+        std::string_view{"TRANSVERSE SHEAR STIFFNESS"},
+    };
+    return std::ranges::find(supported, keyword) != supported.end();
+}
+
+std::optional<KeywordLine> parse_keyword_line(
+    const std::string_view line,
+    const SourceLocation& source,
+    ParseDeckResult& error) {
+    const std::vector<std::string> fields = split_fields(line.substr(1));
+    if (fields.empty() || fields[0].empty()) {
+        error = syntax_failure(
+            "abaqus.syntax.empty_keyword",
+            "Abaqus keyword name is empty.",
+            source);
+        return std::nullopt;
+    }
+
+    KeywordLine parsed{
+        uppercase_ascii(fields[0]),
+        {},
+        source,
+    };
+    for (std::size_t index = 1; index < fields.size(); ++index) {
+        const std::string_view field = fields[index];
+        if (field.empty()) {
+            continue;
+        }
+
+        const std::size_t equals = field.find('=');
+        const std::string_view key_text =
+            trim(field.substr(0, equals));
+        const std::string_view value_text =
+            equals == std::string_view::npos
+                ? std::string_view{}
+                : trim(field.substr(equals + 1));
+        if (key_text.empty()) {
+            error = syntax_failure(
+                "abaqus.syntax.invalid_parameter",
+                "Abaqus keyword parameter name is empty.",
+                source);
+            return std::nullopt;
+        }
+
+        const std::string key = uppercase_ascii(std::string{key_text});
+        if (!parsed.parameters.emplace(key, value_text).second) {
+            error = syntax_failure(
+                "abaqus.syntax.duplicate_parameter",
+                "Abaqus keyword parameter '" + key +
+                    "' is specified more than once.",
+                source);
+            return std::nullopt;
+        }
+    }
+    return parsed;
+}
+
+const std::string* parameter(
+    const KeywordLine& keyword,
+    const std::string_view name) {
+    const auto found = keyword.parameters.find(name);
+    return found == keyword.parameters.end() ? nullptr : &found->second;
+}
+
+ParseDeckResult missing_parameter(
+    const KeywordLine& keyword,
+    const std::string_view parameter_name) {
+    return syntax_failure(
+        "abaqus.syntax.missing_parameter",
+        "Abaqus *" + keyword.keyword + " requires parameter " +
+            std::string{parameter_name} + ".",
+        keyword.source);
+}
+
+}  // namespace
+
+ParseDeckResult parse_deck(const std::filesystem::path& path) {
+    std::ifstream input{path, std::ios::binary};
+    if (!input) {
+        return failure(
+            DiagnosticStage::io,
+            "abaqus.io.open_failed",
+            "Unable to open Abaqus input file.",
+            SourceLocation{path, 0U, 0U});
+    }
+
+    ParsedDeck deck;
+    Scope scope = Scope::global;
+    std::optional<ParsedPart> current_part;
+    std::optional<ParsedAssembly> current_assembly;
+    std::optional<ParsedInstance> current_instance;
+    DeckRecord* current_record = nullptr;
+
+    std::string line;
+    std::size_t line_number = 0;
+    while (std::getline(input, line)) {
+        ++line_number;
+        if (line_number == 1U && line.starts_with("\xEF\xBB\xBF")) {
+            line.erase(0, 3);
+        }
+
+        const std::size_t first_nonspace =
+            line.find_first_not_of(" \t\f\v\r");
+        if (first_nonspace == std::string::npos) {
+            continue;
+        }
+        const std::string_view content = trim(line);
+        if (content.starts_with("**")) {
+            continue;
+        }
+
+        if (!content.starts_with('*')) {
+            const std::vector<std::string> fields = split_fields(content);
+            if (scope == Scope::instance) {
+                current_instance->transform_data.push_back(fields);
+            } else if (current_record != nullptr) {
+                current_record->data.push_back(fields);
+            } else {
+                return syntax_failure(
+                    "abaqus.syntax.data_without_keyword",
+                    "Abaqus data line has no preceding keyword record.",
+                    SourceLocation{path, line_number, first_nonspace + 1U});
+            }
+            continue;
+        }
+
+        const SourceLocation source{
+            path,
+            line_number,
+            first_nonspace + 1U,
+        };
+        ParseDeckResult keyword_error;
+        std::optional<KeywordLine> parsed =
+            parse_keyword_line(content, source, keyword_error);
+        if (!parsed.has_value()) {
+            return keyword_error;
+        }
+        KeywordLine& keyword = *parsed;
+        current_record = nullptr;
+
+        if (keyword.keyword == "PART") {
+            if (scope != Scope::global) {
+                return syntax_failure(
+                    "abaqus.syntax.invalid_part_scope",
+                    "*PART is only valid in global input scope.",
+                    source);
+            }
+            const std::string* name = parameter(keyword, "NAME");
+            if (name == nullptr || name->empty()) {
+                return missing_parameter(keyword, "NAME");
+            }
+            current_part = ParsedPart{*name, {}, source};
+            scope = Scope::part;
+            continue;
+        }
+
+        if (keyword.keyword == "END PART") {
+            if (scope != Scope::part || !current_part.has_value()) {
+                return syntax_failure(
+                    "abaqus.syntax.unexpected_end_part",
+                    "*END PART does not match an open *PART.",
+                    source);
+            }
+            deck.parts.push_back(std::move(*current_part));
+            current_part.reset();
+            scope = Scope::global;
+            continue;
+        }
+
+        if (keyword.keyword == "ASSEMBLY") {
+            if (scope != Scope::global) {
+                return syntax_failure(
+                    "abaqus.syntax.invalid_assembly_scope",
+                    "*ASSEMBLY is only valid in global input scope.",
+                    source);
+            }
+            if (deck.assembly.has_value() ||
+                current_assembly.has_value()) {
+                return syntax_failure(
+                    "abaqus.syntax.multiple_assemblies",
+                    "ParsedDeck can preserve only one *ASSEMBLY.",
+                    source);
+            }
+            const std::string* name = parameter(keyword, "NAME");
+            if (name == nullptr || name->empty()) {
+                return missing_parameter(keyword, "NAME");
+            }
+            current_assembly = ParsedAssembly{*name, {}, {}, source};
+            scope = Scope::assembly;
+            continue;
+        }
+
+        if (keyword.keyword == "END ASSEMBLY") {
+            if (scope != Scope::assembly ||
+                !current_assembly.has_value()) {
+                return syntax_failure(
+                    "abaqus.syntax.unexpected_end_assembly",
+                    "*END ASSEMBLY does not match an open *ASSEMBLY.",
+                    source);
+            }
+            deck.assembly = std::move(*current_assembly);
+            current_assembly.reset();
+            scope = Scope::global;
+            continue;
+        }
+
+        if (keyword.keyword == "INSTANCE") {
+            if (scope != Scope::assembly ||
+                !current_assembly.has_value()) {
+                return syntax_failure(
+                    "abaqus.syntax.invalid_instance_scope",
+                    "*INSTANCE is only valid in an open *ASSEMBLY.",
+                    source);
+            }
+            const std::string* name = parameter(keyword, "NAME");
+            if (name == nullptr || name->empty()) {
+                return missing_parameter(keyword, "NAME");
+            }
+            const std::string* part_name = parameter(keyword, "PART");
+            if (part_name == nullptr || part_name->empty()) {
+                return missing_parameter(keyword, "PART");
+            }
+            current_instance =
+                ParsedInstance{*name, *part_name, {}, source};
+            scope = Scope::instance;
+            continue;
+        }
+
+        if (keyword.keyword == "END INSTANCE") {
+            if (scope != Scope::instance ||
+                !current_instance.has_value() ||
+                !current_assembly.has_value()) {
+                return syntax_failure(
+                    "abaqus.syntax.unexpected_end_instance",
+                    "*END INSTANCE does not match an open *INSTANCE.",
+                    source);
+            }
+            current_assembly->instances.push_back(
+                std::move(*current_instance));
+            current_instance.reset();
+            scope = Scope::assembly;
+            continue;
+        }
+
+        if (!is_supported_record(keyword.keyword)) {
+            return syntax_failure(
+                "abaqus.unsupported_keyword",
+                "Unsupported Abaqus keyword *" + keyword.keyword + ".",
+                source);
+        }
+
+        DeckRecord next_record{
+            std::move(keyword.keyword),
+            std::move(keyword.parameters),
+            {},
+            source,
+        };
+        switch (scope) {
+            case Scope::global:
+                deck.global_records.push_back(std::move(next_record));
+                current_record = &deck.global_records.back();
+                break;
+            case Scope::part:
+                current_part->records.push_back(std::move(next_record));
+                current_record = &current_part->records.back();
+                break;
+            case Scope::assembly:
+                current_assembly->records.push_back(
+                    std::move(next_record));
+                current_record = &current_assembly->records.back();
+                break;
+            case Scope::instance:
+                return syntax_failure(
+                    "abaqus.syntax.instance_local_keyword",
+                    "Keyword records inside *INSTANCE are unsupported.",
+                    source);
+        }
+    }
+
+    if (input.bad()) {
+        return failure(
+            DiagnosticStage::io,
+            "abaqus.io.read_failed",
+            "Failed while reading Abaqus input file.",
+            SourceLocation{path, line_number, 0U});
+    }
+
+    if (current_instance.has_value()) {
+        return syntax_failure(
+            "abaqus.syntax.unclosed_instance",
+            "Abaqus *INSTANCE is not closed by *END INSTANCE.",
+            current_instance->source);
+    }
+    if (current_part.has_value()) {
+        return syntax_failure(
+            "abaqus.syntax.unclosed_part",
+            "Abaqus *PART is not closed by *END PART.",
+            current_part->source);
+    }
+    if (current_assembly.has_value()) {
+        return syntax_failure(
+            "abaqus.syntax.unclosed_assembly",
+            "Abaqus *ASSEMBLY is not closed by *END ASSEMBLY.",
+            current_assembly->source);
+    }
+
+    return {std::move(deck), {}};
+}
+
+}  // namespace fesa
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index a87e8b2..e418d76 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -110,3 +110,33 @@ add_test(
     NAME DomainValidation
     COMMAND "$<TARGET_FILE:fesa_model_value_tests>" --gtest_filter=*DomainValidation*
 )
+
+add_executable(fesa_abaqus_parser_tests
+    unit/io/abaqus/parser_test.cpp
+)
+
+target_compile_features(fesa_abaqus_parser_tests PRIVATE cxx_std_20)
+target_compile_options(fesa_abaqus_parser_tests PRIVATE /W4 /permissive- /EHsc)
+target_compile_definitions(
+    fesa_abaqus_parser_tests
+    PRIVATE
+        FESA_TEST_SOURCE_DIR="${CMAKE_CURRENT_SOURCE_DIR}"
+)
+
+target_link_libraries(fesa_abaqus_parser_tests
+    PRIVATE
+        fesa_core
+        GTest::gtest_main
+)
+
+add_test(
+    NAME AbaqusParser
+    COMMAND "$<TARGET_FILE:fesa_abaqus_parser_tests>"
+        --gtest_filter=AbaqusParser.*
+)
+
+add_test(
+    NAME ScopedDeck
+    COMMAND "$<TARGET_FILE:fesa_abaqus_parser_tests>"
+        --gtest_filter=ScopedDeck.*
+)
diff --git a/tests/fixtures/abaqus/minimal_cantilever.inp b/tests/fixtures/abaqus/minimal_cantilever.inp
new file mode 100644
index 0000000..39f876c
--- /dev/null
+++ b/tests/fixtures/abaqus/minimal_cantilever.inp
@@ -0,0 +1,26 @@
+** Minimal flat/orphan-mesh cantilever syntax fixture.
+
+*nOdE
+1, 0.0, 0.0, 0.0
+** Comments and blank lines do not terminate the current data record.
+
+2, 1.0, 0.0, 0.0,
+*eLeMeNt, TYPE=B31, elset=Beam
+1, 1, 2
+*NSET, NSET=Fixed
+1
+*ELSET, ELSET=Beam
+1
+*MATERIAL, NAME=Steel
+*ELASTIC
+210000.0, 0.3
+*BEAM GENERAL SECTION, SECTION=GENERAL, ELSET=Beam, MATERIAL=Steel
+1.0, 1.0, 1.0, 1.0, 1.0
+0.0, 1.0, 0.0
+*BOUNDARY
+Fixed, 1, 6
+*STEP, NAME=Load
+*STATIC
+*CLOAD
+2, 2, -1.0
+*END STEP
diff --git a/tests/fixtures/abaqus/minimal_part_instance_cantilever.inp b/tests/fixtures/abaqus/minimal_part_instance_cantilever.inp
new file mode 100644
index 0000000..17c4a2c
--- /dev/null
+++ b/tests/fixtures/abaqus/minimal_part_instance_cantilever.inp
@@ -0,0 +1,37 @@
+** Minimal scoped cantilever syntax fixture.
+*PART, NAME=BeamPart
+*NODE
+1, 0.0, 0.0, 0.0
+2, 1.0, 0.0, 0.0
+*ELEMENT, TYPE=B31, ELSET=Beam
+1, 1, 2
+*NSET, NSET=Fixed
+1
+*NSET, NSET=Tip
+2
+*ELSET, ELSET=Beam
+1
+*BEAM GENERAL SECTION, SECTION=GENERAL, ELSET=Beam, MATERIAL=Steel
+1.0, 1.0, 1.0, 1.0, 1.0
+0.0, 1.0, 0.0
+*END PART
+
+*ASSEMBLY, NAME=RootAssembly
+*INSTANCE, NAME=Beam-1, PART=BeamPart
+*END INSTANCE
+*NSET, NSET=Fixed, INSTANCE=Beam-1
+1
+*NSET, NSET=Tip, INSTANCE=Beam-1
+2
+*END ASSEMBLY
+
+*MATERIAL, NAME=Steel
+*ELASTIC
+210000.0, 0.3
+*STEP, NAME=Load
+*STATIC
+*BOUNDARY
+Fixed, 1, 6
+*CLOAD
+Tip, 2, -1.0
+*END STEP
diff --git a/tests/unit/io/abaqus/parser_test.cpp b/tests/unit/io/abaqus/parser_test.cpp
new file mode 100644
index 0000000..7692f3f
--- /dev/null
+++ b/tests/unit/io/abaqus/parser_test.cpp
@@ -0,0 +1,235 @@
+#include <fesa/io/abaqus/parser.hpp>
+
+#include <algorithm>
+#include <cstddef>
+#include <filesystem>
+#include <fstream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <utility>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+namespace {
+
+class TemporaryDeck final {
+public:
+    TemporaryDeck(std::string_view name, std::string_view contents)
+        : path_{std::filesystem::path{testing::TempDir()} / name} {
+        std::ofstream output{path_, std::ios::binary};
+        output.write(
+            contents.data(), static_cast<std::streamsize>(contents.size()));
+        if (!output) {
+            throw std::runtime_error{"Failed to write temporary Abaqus deck."};
+        }
+    }
+
+    ~TemporaryDeck() {
+        std::error_code error;
+        std::filesystem::remove(path_, error);
+    }
+
+    TemporaryDeck(const TemporaryDeck&) = delete;
+    TemporaryDeck& operator=(const TemporaryDeck&) = delete;
+
+    [[nodiscard]] const std::filesystem::path& path() const noexcept {
+        return path_;
+    }
+
+private:
+    std::filesystem::path path_;
+};
+
+std::filesystem::path fixture_path(std::string_view name) {
+    return std::filesystem::path{FESA_TEST_SOURCE_DIR} / "fixtures" /
+           "abaqus" / name;
+}
+
+const fesa::DeckRecord& record(
+    const std::vector<fesa::DeckRecord>& records,
+    const std::string_view keyword) {
+    const auto found = std::ranges::find(
+        records, keyword, &fesa::DeckRecord::keyword);
+    if (found == records.end()) {
+        throw std::runtime_error{"Expected deck record was not parsed."};
+    }
+    return *found;
+}
+
+TEST(AbaqusParser, ParsesCaseInsensitiveKeywordsCommentsAndCommaFields) {
+    const auto path = fixture_path("minimal_cantilever.inp");
+
+    const auto result = fesa::parse_deck(path);
+
+    ASSERT_TRUE(result.deck.has_value());
+    EXPECT_TRUE(result.diagnostics.empty());
+    EXPECT_TRUE(result.deck->parts.empty());
+    EXPECT_FALSE(result.deck->assembly.has_value());
+
+    const auto& nodes = record(result.deck->global_records, "NODE");
+    ASSERT_EQ(nodes.data.size(), 2U);
+    EXPECT_EQ(nodes.data[0], (std::vector<std::string>{
+                                 "1", "0.0", "0.0", "0.0"}));
+    EXPECT_EQ(nodes.data[1], (std::vector<std::string>{
+                                 "2", "1.0", "0.0", "0.0", ""}));
+    EXPECT_EQ(nodes.source.file, path);
+    EXPECT_EQ(nodes.source.line, 3U);
+    EXPECT_EQ(nodes.source.column, 1U);
+
+    const auto& element = record(result.deck->global_records, "ELEMENT");
+    EXPECT_EQ(element.parameters.at("TYPE"), "B31");
+    EXPECT_EQ(element.parameters.at("ELSET"), "Beam");
+    EXPECT_EQ(element.source.line, 8U);
+}
+
+TEST(AbaqusParser, PreservesUtf8ParameterValues) {
+    const std::string utf8_name{
+        "\xEB\xB9\x94\xEB\xB6\x80\xED\x92\x88"};
+    const TemporaryDeck input{
+        "fesa-parser-utf8.inp",
+        "*MATERIAL, NAME=" + utf8_name + "\n"
+        "*ELASTIC\n"
+        "210000.0, 0.3\n"};
+
+    const auto result = fesa::parse_deck(input.path());
+
+    ASSERT_TRUE(result.deck.has_value());
+    ASSERT_TRUE(result.diagnostics.empty());
+    const auto& material = record(result.deck->global_records, "MATERIAL");
+    EXPECT_EQ(material.parameters.at("NAME"), utf8_name);
+}
+
+TEST(AbaqusParser, RejectsUnsupportedKeywordsInsteadOfIgnoringThem) {
+    const TemporaryDeck input{
+        "fesa-parser-unsupported.inp",
+        "** The error source must identify the keyword line.\n"
+        "*INCLUDE, INPUT=other.inp\n"};
+
+    const auto result = fesa::parse_deck(input.path());
+
+    EXPECT_FALSE(result.deck.has_value());
+    ASSERT_EQ(result.diagnostics.size(), 1U);
+    EXPECT_EQ(
+        result.diagnostics[0].stage, fesa::DiagnosticStage::syntax);
+    EXPECT_EQ(
+        result.diagnostics[0].code, "abaqus.unsupported_keyword");
+    ASSERT_TRUE(result.diagnostics[0].source.has_value());
+    EXPECT_EQ(result.diagnostics[0].source->file, input.path());
+    EXPECT_EQ(result.diagnostics[0].source->line, 2U);
+}
+
+TEST(ScopedDeck, PreservesPartAssemblyAndInstanceScopes) {
+    const auto path =
+        fixture_path("minimal_part_instance_cantilever.inp");
+
+    const auto result = fesa::parse_deck(path);
+
+    ASSERT_TRUE(result.deck.has_value());
+    EXPECT_TRUE(result.diagnostics.empty());
+    ASSERT_EQ(result.deck->parts.size(), 1U);
+    EXPECT_EQ(result.deck->parts[0].name, "BeamPart");
+    EXPECT_EQ(result.deck->parts[0].source.file, path);
+    EXPECT_EQ(result.deck->parts[0].source.line, 2U);
+    EXPECT_EQ(record(result.deck->parts[0].records, "NODE").source.line, 3U);
+
+    ASSERT_TRUE(result.deck->assembly.has_value());
+    EXPECT_EQ(result.deck->assembly->name, "RootAssembly");
+    EXPECT_EQ(result.deck->assembly->source.line, 19U);
+    ASSERT_EQ(result.deck->assembly->instances.size(), 1U);
+    EXPECT_EQ(result.deck->assembly->instances[0].name, "Beam-1");
+    EXPECT_EQ(result.deck->assembly->instances[0].part_name, "BeamPart");
+    EXPECT_EQ(result.deck->assembly->instances[0].source.line, 20U);
+    EXPECT_TRUE(
+        result.deck->assembly->instances[0].transform_data.empty());
+    EXPECT_EQ(
+        record(result.deck->assembly->records, "NSET")
+            .parameters.at("INSTANCE"),
+        "Beam-1");
+
+    EXPECT_NE(
+        std::ranges::find(
+            result.deck->global_records,
+            "MATERIAL",
+            &fesa::DeckRecord::keyword),
+        result.deck->global_records.end());
+}
+
+TEST(ScopedDeck, PreservesInstanceTransformDataWithoutApplyingIt) {
+    const TemporaryDeck input{
+        "fesa-parser-transform.inp",
+        "*PART, NAME=BeamPart\n"
+        "*END PART\n"
+        "*ASSEMBLY, NAME=RootAssembly\n"
+        "*INSTANCE, NAME=Beam-1, PART=BeamPart\n"
+        "1.0, 2.0, 3.0\n"
+        "0.0, 0.0, 1.0, 90.0\n"
+        "*END INSTANCE\n"
+        "*END ASSEMBLY\n"};
+
+    const auto result = fesa::parse_deck(input.path());
+
+    ASSERT_TRUE(result.deck.has_value());
+    ASSERT_TRUE(result.deck->assembly.has_value());
+    ASSERT_EQ(result.deck->assembly->instances.size(), 1U);
+    EXPECT_EQ(
+        result.deck->assembly->instances[0].transform_data,
+        (std::vector<std::vector<std::string>>{
+            {"1.0", "2.0", "3.0"},
+            {"0.0", "0.0", "1.0", "90.0"}}));
+}
+
+TEST(ScopedDeck, ReportsUnexpectedAndUnclosedScopeTerminators) {
+    struct Case final {
+        std::string_view name;
+        std::string_view contents;
+        std::string_view code;
+        std::size_t line;
+    };
+    const Case cases[]{
+        {
+            "fesa-parser-unexpected-end-part.inp",
+            "*END PART\n",
+            "abaqus.syntax.unexpected_end_part",
+            1U,
+        },
+        {
+            "fesa-parser-unclosed-part.inp",
+            "*PART, NAME=BeamPart\n"
+            "*NODE\n"
+            "1, 0.0, 0.0, 0.0\n",
+            "abaqus.syntax.unclosed_part",
+            1U,
+        },
+        {
+            "fesa-parser-unexpected-end-instance.inp",
+            "*ASSEMBLY, NAME=RootAssembly\n"
+            "*END INSTANCE\n",
+            "abaqus.syntax.unexpected_end_instance",
+            2U,
+        },
+        {
+            "fesa-parser-unclosed-assembly.inp",
+            "*ASSEMBLY, NAME=RootAssembly\n",
+            "abaqus.syntax.unclosed_assembly",
+            1U,
+        },
+    };
+
+    for (const auto& test_case : cases) {
+        const TemporaryDeck input{test_case.name, test_case.contents};
+
+        const auto result = fesa::parse_deck(input.path());
+
+        SCOPED_TRACE(test_case.name);
+        EXPECT_FALSE(result.deck.has_value());
+        ASSERT_EQ(result.diagnostics.size(), 1U);
+        EXPECT_EQ(result.diagnostics[0].code, test_case.code);
+        ASSERT_TRUE(result.diagnostics[0].source.has_value());
+        EXPECT_EQ(result.diagnostics[0].source->line, test_case.line);
+    }
+}
+
+}  // namespace