diff --git a/src/ocrmypdf/_options.py b/src/ocrmypdf/_options.py
index 04d012c3..8eb6fdc1 100644
--- a/src/ocrmypdf/_options.py
+++ b/src/ocrmypdf/_options.py
@@ -20,6 +20,9 @@ from ocrmypdf._defaults import DEFAULT_LANGUAGE, DEFAULT_ROTATE_PAGES_THRESHOLD
 from ocrmypdf.exceptions import BadArgsError
 from ocrmypdf.helpers import monotonic
 
+# Import plugin option models - these will be available after plugins are loaded
+# We'll use forward references and handle imports dynamically
+
 log = logging.getLogger(__name__)
 
 PathOrIO = BinaryIO | IOBase | Path | str | bytes
@@ -137,9 +140,50 @@ class OCROptions(BaseModel):
         """Compatibility alias for jpg_quality."""
         self.jpg_quality = value
 
+    # Backward compatibility properties for jbig2 options
+    @property
+    def jbig2_lossy(self):
+        """Backward compatibility for jbig2_lossy."""
+        return getattr(self, '_jbig2_lossy', None)
+
+    @jbig2_lossy.setter
+    def jbig2_lossy(self, value):
+        """Backward compatibility for jbig2_lossy."""
+        self._jbig2_lossy = value
+
+    @property
+    def jbig2_page_group_size(self):
+        """Backward compatibility for jbig2_page_group_size."""
+        return getattr(self, '_jbig2_page_group_size', None)
+
+    @jbig2_page_group_size.setter
+    def jbig2_page_group_size(self, value):
+        """Backward compatibility for jbig2_page_group_size."""
+        self._jbig2_page_group_size = value
+
+    @property
+    def jbig2_threshold(self):
+        """Backward compatibility for jbig2_threshold."""
+        return getattr(self, '_jbig2_threshold', 0.85)
+
+    @jbig2_threshold.setter
+    def jbig2_threshold(self, value):
+        """Backward compatibility for jbig2_threshold."""
+        self._jbig2_threshold = value
+
     # Advanced options
     max_image_mpixels: float = 250.0
     pdf_renderer: str = 'auto'
+    rotate_pages_threshold: float = DEFAULT_ROTATE_PAGES_THRESHOLD
+    user_words: os.PathLike | None = None
+    user_patterns: os.PathLike | None = None
+    fast_web_view: float = 1.0
+    continue_on_soft_render_error: bool | None = None
+
+    # Plugin option namespaces (for backward compatibility, will be removed in Phase 5)
+    # These will be populated dynamically based on loaded plugins
+    
+    # Legacy tesseract options (for backward compatibility)
     tesseract_config: list[str] = []
     tesseract_pagesegmode: int | None = None
     tesseract_oem: int | None = None
@@ -148,13 +192,10 @@ class OCROptions(BaseModel):
     tesseract_non_ocr_timeout: float | None = None
     tesseract_downsample_above: int = 32767
     tesseract_downsample_large_images: bool | None = None
-    rotate_pages_threshold: float = DEFAULT_ROTATE_PAGES_THRESHOLD
+    
+    # Legacy ghostscript options (for backward compatibility)
     pdfa_image_compression: str | None = None
     color_conversion_strategy: str = "LeaveColorUnchanged"
-    user_words: os.PathLike | None = None
-    user_patterns: os.PathLike | None = None
-    fast_web_view: float = 1.0
-    continue_on_soft_render_error: bool | None = None
 
     # Plugin system
     plugins: Sequence[Path | str] | None = None
diff --git a/src/ocrmypdf/builtin_plugins/ghostscript.py b/src/ocrmypdf/builtin_plugins/ghostscript.py
index d5fbd92f..550ac599 100644
--- a/src/ocrmypdf/builtin_plugins/ghostscript.py
+++ b/src/ocrmypdf/builtin_plugins/ghostscript.py
@@ -5,8 +5,10 @@
 from __future__ import annotations
 
 import logging
+from typing import Annotated
 
 from packaging.version import Version
+from pydantic import BaseModel, Field
 
 from ocrmypdf import hookimpl
 from ocrmypdf._exec import ghostscript
@@ -20,6 +22,13 @@ log = logging.getLogger(__name__)
 BLACKLISTED_GS_VERSIONS: frozenset[Version] = frozenset()
 
 
+class GhostscriptOptions(BaseModel):
+    """Options specific to Ghostscript operations."""
+    
+    color_conversion_strategy: Annotated[str, Field(description="Ghostscript color conversion strategy")] = "LeaveColorUnchanged"
+    pdfa_image_compression: Annotated[str, Field(description="PDF/A image compression method")] = "auto"
+
+
 @hookimpl
 def add_options(parser):
     gs = parser.add_argument_group("Ghostscript", "Advanced control of Ghostscript")
diff --git a/src/ocrmypdf/builtin_plugins/optimize.py b/src/ocrmypdf/builtin_plugins/optimize.py
index ff841f93..e5e3ffc6 100644
--- a/src/ocrmypdf/builtin_plugins/optimize.py
+++ b/src/ocrmypdf/builtin_plugins/optimize.py
@@ -8,6 +8,9 @@ import argparse
 import logging
 from collections.abc import Sequence
 from pathlib import Path
+from typing import Annotated
+
+from pydantic import BaseModel, Field
 
 from ocrmypdf import Executor, PdfContext, hookimpl
 from ocrmypdf._exec import jbig2enc, pngquant
@@ -19,6 +22,17 @@ from ocrmypdf.subprocess import check_external_program
 log = logging.getLogger(__name__)
 
 
+class OptimizeOptions(BaseModel):
+    """Options specific to PDF optimization."""
+    
+    level: Annotated[int, Field(ge=0, le=3, description="Optimization level (0=none, 1=safe, 2=lossy, 3=aggressive)")] = 1
+    jpeg_quality: Annotated[int, Field(ge=0, le=100, description="JPEG quality level for optimization")] = 0
+    png_quality: Annotated[int, Field(ge=0, le=100, description="PNG quality level for optimization")] = 0
+    jbig2_lossy: Annotated[bool, Field(description="Enable JBIG2 lossy compression")] = False
+    jbig2_page_group_size: Annotated[int, Field(ge=1, le=10000, description="Number of pages to consider for JBIG2 compression")] = 0
+    jbig2_threshold: Annotated[float, Field(ge=0.4, le=0.9, description="JBIG2 symbol classification threshold")] = 0.85
+
+
 @hookimpl
 def add_options(parser):
     optimizing = parser.add_argument_group(
diff --git a/src/ocrmypdf/builtin_plugins/tesseract_ocr.py b/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
index 765647b5..1f8c94e4 100644
--- a/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
+++ b/src/ocrmypdf/builtin_plugins/tesseract_ocr.py
@@ -7,8 +7,10 @@ from __future__ import annotations
 import argparse
 import logging
 import os
+from typing import Annotated
 
 from PIL import Image
+from pydantic import BaseModel, Field
 
 from ocrmypdf import hookimpl
 from ocrmypdf._exec import tesseract
@@ -23,6 +25,19 @@ from ocrmypdf.subprocess import check_external_program
 log = logging.getLogger(__name__)
 
 
+class TesseractOptions(BaseModel):
+    """Options specific to Tesseract OCR engine."""
+    
+    config: Annotated[list[str], Field(description="Additional Tesseract configuration files")] = []
+    pagesegmode: Annotated[int | None, Field(ge=0, le=13, description="Set Tesseract page segmentation mode")] = None
+    oem: Annotated[int | None, Field(ge=0, le=3, description="Set Tesseract OCR engine mode")] = None
+    thresholding: Annotated[int | None, Field(description="Set Tesseract input image thresholding mode")] = None
+    timeout: Annotated[float, Field(ge=0, description="Timeout for OCR operations in seconds")] = 180.0
+    non_ocr_timeout: Annotated[float, Field(ge=0, description="Timeout for non-OCR operations in seconds")] = 180.0
+    downsample_large_images: Annotated[bool, Field(description="Downsample large images before OCR")] = True
+    downsample_above: Annotated[int, Field(ge=100, le=32767, description="Downsample images larger than this pixel size")] = 32767
+
+
 @hookimpl
 def add_options(parser):
     tess = parser.add_argument_group("Tesseract", "Advanced control of Tesseract OCR")
@@ -152,6 +167,8 @@ def check_options(options):
             "Please upgrade to a newer or supported older version."
         )
 
+    # Validate Tesseract-specific options using the new model
+    # For now, we still access options directly for backward compatibility
     if not tesseract.has_thresholding() and options.tesseract_thresholding != 0:
         log.warning(
             "The installed version of Tesseract does not support changes to its "
diff --git a/src/ocrmypdf/cli.py b/src/ocrmypdf/cli.py
index f7552177..c097d026 100644
--- a/src/ocrmypdf/cli.py
+++ b/src/ocrmypdf/cli.py
@@ -463,6 +463,10 @@ def namespace_to_options(ns) -> OCROptions:
     if 'work_folder' in extra_attrs and 'input_file' not in known_fields:
         known_fields['input_file'] = '/dev/null'  # Placeholder
 
+    # Handle backward compatibility for plugin options
+    # Map CLI arguments to the appropriate fields for now
+    # In Phase 2, this will be handled by plugin option models
+    
     instance = OCROptions(**known_fields)
     instance.extra_attrs = extra_attrs
     return instance