diff --git a/examples/post.v3.eamxx.cfg b/examples/post.v3.eamxx.cfg
new file mode 100644
index 00000000..541d9b7c
--- /dev/null
+++ b/examples/post.v3.eamxx.cfg
@@ -0,0 +1,190 @@
+# Example: EAMxx → CMIP and e3sm_diags, initially contributed by Shixuan Zhang.
+# Reproduces the cfg from issue #820 plus e3sm_diags-related tasks.
+# (https://github.com/E3SM-Project/zppy/issues/820)
+#
+# Demonstrates:
+#   - EAMxx CMORization end-to-end (issue #817)
+#   - The fix to the fragile component-detection gate (now uses prc_typ),
+#     so input_component="eamxx" with input_files="AVERAGE.nmonths_x1" works
+#   - EAMxx-specific ncremap flags (--ps_nm=${file}/ps, --vrt_in=vert_L128.nc)
+#     auto-emitted when prc_typ == 'eamxx'
+#   - climo, ts, e3sm_to_cmip, and e3sm_diags wiring for an EAMxx run
+#
+# Run with: zppy -c examples/post.v3.eamxx.cfg
+[default]
+input = /pscratch/sd/z/zhan391/e3smv4_project/ne256pg2_ne256pg2.F20TR-SCREAMv1.July-1.spanc800.2xauto.acc150.n0032.test2.1
+output = /pscratch/sd/c/chengzhu/tests/ne256pg2_ne256pg2.F20TR-SCREAMv1.July-1.spanc800.2xauto.acc150.n0032.test2.1_05182026
+case = ne256pg2_ne256pg2.F20TR-SCREAMv1.July-1.spanc800.2xauto.acc150.n0032.test2.1
+www = /global/cfs/cdirs/e3sm/www/chengzhu/tests/zppy_for_eamxx_05182026
+partition = "debug"
+account = "e3sm"
+campaign = "water_cycle"
+debug = False
+#environment_commands = "source /global/common/software/e3sm/anaconda_envs/test_e3sm_unified_1.13.0rc10_pm-cpu.sh"
+
+[climo]
+active = True
+walltime = "2:00:00"
+years = "1995:2004:10",
+
+  [[ atm_monthly_180x360_aave ]]
+  # The following e3sm_diags sets require it:
+  # "lat_lon", "zonal_mean_xy", "zonal_mean_2d", "polar", "cosp_histogram",
+  # "meridional_mean_2d", "annual_cycle_zonal_mean", "zonal_mean_2d_stratosphere",
+  # "aerosol_aeronet", "aerosol_budget"
+  input_component = "eamxx"
+  case = "1ma_ne30pg2"
+  input_files = "AVERAGE.nmonths_x1"
+  frequency = "monthly"
+  input_subdir = "run/"
+  mapping_file = map_ne30pg2_to_cmip6_180x360_aave.20200201.nc
+
+  [[ atm_monthly_diurnal_8xdaily_180x360_aave ]]
+  # The following e3sm_diags sets require it:
+  # "diurnal_cycle"
+  input_component = "eamxx"
+  case = "3ha_ne30pg2"
+  input_files = "AVERAGE.nhours_x3"
+  input_subdir = "run/"
+  frequency = "diurnal_8xdaily"
+  mapping_file = map_ne30pg2_to_cmip6_180x360_aave.20200201.nc
+  vars = "precip_liq_surf_mass_flux,precip_ice_surf_mass_flux"
+  # Bump walltime for a potential performance issue in ncclimo for processing eamxx high freq data.
+  walltime = "4:00:00"
+
+  [[ land_monthly_climo ]]
+  active = True
+  # This subtask is a dependency for the e3sm_diags task's lnd_monthly_mvm_lnd subtask.
+  # The following e3sm_diags sets require it:
+  # "lat_lon_land"
+  input_component = "elm"
+  frequency = "monthly"
+  input_files = "elm.h0"
+  input_subdir = "run/"
+  vars = "" # Setting this as "" will tell zppy to use ALL variables
+
+  [[ land_monthly_180x360_traave ]]
+  active = True
+  input_component = "elm"
+  frequency = "monthly"
+  input_files = "elm.h0"
+  input_subdir = "run/"
+  mapping_file = "map_ne256pg2_to_cmip6_180x360_traave.20250301.nc"
+  vars = ""
+
+[ts]
+active = True
+walltime = "00:30:00"
+years = "1995:2004:5"
+ts_num_years=5
+#qos = "debug"
+
+  [[atm_monthly_180x360_aave]]
+  # Merged 2D+3D atm timeseries: vrt_remap_vars selectively vert-remaps the
+  # 3D vars into a sibling ts_vrt_remap/ directory, so downstream e3sm_to_cmip
+  # sees a single clean ts subsection.
+  input_component = "eamxx"
+  input_subdir = "run/"
+  case = "1ma_ne30pg2"
+  input_files = "AVERAGE.nmonths_x1"
+  frequency = "monthly"
+  mapping_file = map_ne30pg2_to_cmip6_180x360_aave.20200201.nc
+  vars="ps,surf_radiative_T,SeaLevelPressure,IceWaterPath,qv_2m,precip_liq_surf_mass_flux,precip_ice_surf_mass_flux,omega_at_500hPa,omega_at_700hPa,omega_at_850hPa,T_mid_at_700hPa,T_2m,surface_upward_latent_heat_flux,surf_sens_flux,z_mid_at_700hPa,wind_speed_10m,surf_evap,U_at_10m_above_surface,V_at_10m_above_surface,LW_clrsky_flux_dn_at_model_bot,LW_clrsky_flux_up_at_model_top,LW_flux_dn_at_model_bot,LW_flux_up_at_model_bot,LW_flux_up_at_model_top,SW_clrsky_flux_dn_at_model_bot,SW_clrsky_flux_dn_at_model_top,SW_clrsky_flux_up_at_model_bot,SW_clrsky_flux_up_at_model_top,SW_flux_dn_at_model_bot,SW_flux_dn_at_model_top,SW_flux_up_at_model_bot,SW_flux_up_at_model_top,ShortwaveCloudForcing,LongwaveCloudForcing,isccp_cldtot,U,V,T_mid,z_mid,omega,RelativeHumidity,p_mid,qv"
+  # NOTE: ncclimo --prc_typ=eamxx does NOT auto-extract ps/hyai/hyam/hybi/hybm
+  # for 3D vars the way --prc_typ=cam/eam does due to a meta data issue, so we must list them explicitly
+  # in extra_vars. ps is load-bearing for the vrt_remap step (ts.bash:138
+  # passes --ps_nm=${file}/ps to ncremap).
+  # If ncclimo and eamxx is fixed upstream to mirror cam/eam behavior, drop
+  # ps + hybrid coeffs here.
+  extra_vars= "ps,hyai,hyam,hybi,hybm,area,landfrac,ocnfrac"
+  vrt_remap_vars = "U,V,T_mid,z_mid,omega,RelativeHumidity,p_mid,qv"
+
+  [[ atm_daily_180x360_aave ]]
+  active = True
+  # This subtask is a dependency for the e3sm_diags task's atm_monthly_180x360 subtask.
+  # The following e3sm_diags sets require it:
+  # "tropical_subseasonal", "precip_pdf"
+  input_component = "eamxx"
+  case = "1da_ne30pg2"
+  input_files = "AVERAGE.ndays_x1"
+  frequency = "daily"
+  input_subdir = "run/"
+  mapping_file = map_ne30pg2_to_cmip6_180x360_aave.20200201.nc
+  # Needed for Wheeler Kiladis
+  vars = "LW_flux_up_at_model_top,precip_liq_surf_mass_flux,precip_ice_surf_mass_flux,U_at_850hPa"
+  # For this simulation's "1da_ne30pg2.AVERAGE.ndays_x1" stream, each file
+  # holds one daily average (1 day, 1 timestep). Override the zppy defaults
+  # (dpf=30, tpd=1) which assume E3SM EAM monthly h0 files; otherwise ncclimo
+  # treats each daily file as 30 days and silently produces ts files whose
+  # contents (~2 months) don't match their filenames.
+  dpf = 1
+  tpd = 1
+
+  [[ atm_monthly_glb ]]
+  active = True
+  # This subtask is a dependency for the global_time_series task.
+  input_component = "eam"
+  input_subdir = "run/"
+  case = "1ma_ne30pg2"
+  input_files = "AVERAGE.nmonths_x1"
+  frequency = "monthly"
+  mapping_file = "glb"
+  vars="ps,surf_radiative_T,SeaLevelPressure,IceWaterPath,qv_2m,precip_liq_surf_mass_flux,precip_ice_surf_mass_flux"
+
+
+  [[ rof_monthly ]]
+  active = True
+  # The following e3sm_diags sets require it:
+  # "streamflow"
+  input_component = "mosart"
+  frequency = "monthly"
+  input_files = "mosart.h0"
+  input_subdir = "run/"
+  mapping_file = ""
+  vars = "RIVER_DISCHARGE_OVER_LAND_LIQ"
+  extra_vars = 'areatotal2'
+
+[e3sm_to_cmip]
+active = True
+frequency = "monthly"
+ts_grid = "180x360_aave"
+ts_num_years=5
+walltime = "00:10:00"
+years = "1995:2004:5"
+qos = "debug"
+
+  [[atm_monthly_180x360_aave]]
+  # Merged subsection matching the [ts] atm_monthly_180x360_aave output.
+  # Without cmip_vars, e3sm_to_cmip uses its built-in default list (~41 vars).
+  # Uncomment to override the default ~41-var list.
+  #cmip_vars = "pr, cltisccp, evspsbl, hfls, hfss, huss, ps, psl, rlds, rldscs, rlus, rlut, rlutcs, rsds, rsdscs, rsdt, rsus, rsuscs, rtmt, uas, vas, sfcWind, tas, ts, ta, ua, va, zg"
+  input_component = "eamxx"
+  case = "1ma_ne30pg2"
+  input_files = "AVERAGE.nmonths_x1"
+
+
+[e3sm_diags]
+active = True
+multiprocessing = True
+num_workers = 8
+ref_start_yr = 1995
+ref_final_yr = 2004
+ts_num_years = 5
+walltime = "2:00:00"
+years = "1995:2004:10",
+
+# case inherits the top-level [default] case; climo output naming includes
+# the stream id automatically via fml_nm, so this subsection can consume
+# both monthly and diurnal climo without per-frequency overrides.
+
+  [[ atm_monthly_180x360_aave ]]
+  # `e3sm_diags` is largely driven by which e3sm_diags sets are requested:
+  sets="lat_lon","zonal_mean_xy","zonal_mean_2d","polar","cosp_histogram","meridional_mean_2d","annual_cycle_zonal_mean","enso_diags","qbo","zonal_mean_2d_stratosphere","aerosol_aeronet","mp_partition","tropical_subseasonal","precip_pdf","streamflow","diurnal_cycle",
+#  sets = #"tc_analysis," # not yet supported for eamxx!
+  climo_diurnal_frequency = "diurnal_8xdaily"
+  climo_diurnal_subsection = "atm_monthly_diurnal_8xdaily_180x360_aave"
+  ts_daily_subsection = "atm_daily_180x360_aave"
+  # ts_subsection defaults to "atm_monthly_180x360_aave" — matches the merged
+  # [ts] subsection above, so no explicit override needed.
+  grid = '180x360_aave'
+  short_name = 'e3sm.amip.EAMXX.test2_1'
diff --git a/tests/test_sections.py b/tests/test_sections.py
index fe21e62b..8b34fd42 100644
--- a/tests/test_sections.py
+++ b/tests/test_sections.py
@@ -120,6 +120,9 @@ def test_sections():
         "mapping_file": "MAPPING_FILE_TS",
         "tpd": 1,
         "vars": "FSNTOA,FLUT,FSNT,FLNT,FSNS,FLNS,SHFLX,QFLX,PRECC,PRECL,PRECSC,PRECSL,TS,TREFHT",
+        "vrt_remap_vars": "",
+        "vrt_in_file": "",
+        "vrt_remap_file": "",
         "years": ["0001:0020:5"],
     }
     compare(actual_section, expected_section)
@@ -135,6 +138,7 @@ def test_sections():
         "case": "CASE",
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dpf": 30,
         "dry_run": False,
         "environment_commands": "",
@@ -171,6 +175,9 @@ def test_sections():
         "ts_num_years": 5,
         "ts_subsection": "",
         "vars": "FSNTOA,FLUT,FSNT,FLNT,FSNS,FLNS,SHFLX,QFLX,PRECC,PRECL,PRECSC,PRECSL,TS,TREFHT",
+        "vrt_remap_vars": "",
+        "vrt_in_file": "",
+        "vrt_remap_file": "",
         "walltime": "02:00:00",
         "www": "WWWW",
         "years": ["0001:0020:5"],
@@ -204,6 +211,7 @@ def test_sections():
         "climo_jobs": 0,
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dry_run": False,
         "environment_commands": "",
         "environment_commands_secondary": "",
@@ -326,6 +334,9 @@ def test_subsections():
             "job_nbr": None,
             "mapping_file": "MAPPING_FILE_TS_GRID1",
             "tpd": None,
+            "vrt_remap_vars": None,
+            "vrt_in_file": None,
+            "vrt_remap_file": None,
             "years": ["0001:0020:5"],
         },
         "ts_grid2": {
@@ -336,9 +347,15 @@ def test_subsections():
             "job_nbr": None,
             "mapping_file": "MAPPING_FILE_TS_GRID2",
             "tpd": None,
+            "vrt_remap_vars": None,
+            "vrt_in_file": None,
+            "vrt_remap_file": None,
             "years": ["0001:0020:10"],
         },
         "vars": "FSNTOA,FLUT,FSNT,FLNT,FSNS,FLNS,SHFLX,QFLX,PRECC,PRECL,PRECSC,PRECSL,TS,TREFHT",
+        "vrt_remap_vars": "",
+        "vrt_in_file": "",
+        "vrt_remap_file": "",
     }
     compare(actual_section, expected_section)
     actual_tasks = get_tasks(config, section_name)
@@ -353,6 +370,7 @@ def test_subsections():
         "case": "CASE",
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dpf": 30,
         "dry_run": False,
         "environment_commands": "",
@@ -389,6 +407,9 @@ def test_subsections():
         "ts_num_years": 5,
         "ts_subsection": "",
         "vars": "FSNTOA,FLUT,FSNT,FLNT,FSNS,FLNS,SHFLX,QFLX,PRECC,PRECL,PRECSC,PRECSL,TS,TREFHT",
+        "vrt_remap_vars": "",
+        "vrt_in_file": "",
+        "vrt_remap_file": "",
         "walltime": "02:00:00",
         "www": "WWWW",
         "years": ["0001:0020:5"],
@@ -404,6 +425,7 @@ def test_subsections():
         "case": "CASE",
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dpf": 30,
         "dry_run": False,
         "environment_commands": "",
@@ -440,6 +462,9 @@ def test_subsections():
         "ts_num_years": 5,
         "ts_subsection": "",
         "vars": "FSNTOA,FLUT,FSNT,FLNT,FSNS,FLNS,SHFLX,QFLX,PRECC,PRECL,PRECSC,PRECSL,TS,TREFHT",
+        "vrt_remap_vars": "",
+        "vrt_in_file": "",
+        "vrt_remap_file": "",
         "walltime": "02:00:00",
         "www": "WWWW",
         "years": ["0001:0020:10"],
@@ -491,6 +516,7 @@ def test_subsections():
         "climo_jobs": 0,
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dry_run": False,
         "environment_commands": "",
         "environment_commands_secondary": "",
@@ -539,6 +565,7 @@ def test_subsections():
         "climo_jobs": 0,
         "constraint": "",
         "debug": False,
+        "default_case": "CASE",
         "dry_run": False,
         "environment_commands": "",
         "environment_commands_secondary": "",
diff --git a/zppy/climo.py b/zppy/climo.py
index 1a4e768b..711b76dc 100644
--- a/zppy/climo.py
+++ b/zppy/climo.py
@@ -35,6 +35,15 @@ def climo(config: ConfigObj, script_dir: str, existing_bundles, job_ids_file):
         set_mapping_file(c)
         set_grid(c)
         set_component_and_prc_typ(c)
+        # Compose the climo output filename prefix. For EAMxx, subsection-level
+        # `case` (e.g., "1ma_ne30pg2") is the stream id ncclimo needs to find
+        # input files; prefixing with the top-level case keeps output names
+        # unified across streams so a single e3sm_diags subsection can consume
+        # both monthly and diurnal climo via one `case` setting.
+        if c["prc_typ"] == "eamxx" and c["case"] != c["default_case"]:
+            c["fml_nm"] = f"{c['default_case']}.{c['case']}"
+        else:
+            c["fml_nm"] = c["case"]
         year_sets: List[Tuple[int, int]] = get_years(c["years"])
         # Loop over year sets
         for s in year_sets:
diff --git a/zppy/defaults/default.ini b/zppy/defaults/default.ini
index d8621747..9fcb02d2 100755
--- a/zppy/defaults/default.ini
+++ b/zppy/defaults/default.ini
@@ -151,6 +151,18 @@ job_nbr = integer(default=0)
 tpd = integer(default=1)
 # Model component having generated input files (eam, eamxx, elm, mosart, ...)
 input_component = string(default="")
+# Vertical regrid (model levels → pressure levels) — applied after ncclimo splits
+# files into per-var time-series. Vars listed here will additionally be regridded
+# and written to a sibling directory `ts_vrt_remap/` parallel to `ts/`, so users
+# can use native-level and pressure-level data at the same time.
+# If empty, no vertical regrid is performed.
+vrt_remap_vars = string(default="")
+# Target vertical grid file (output pressure levels) for ncremap.
+# If empty, zppy defaults to a vrt_remap_plev19.nc under diagnostics_base_path.
+vrt_remap_file = string(default="")
+# Source vertical coordinate file for ncremap. Required for EAMxx (L128 grid).
+# If empty, zppy defaults to a vert_L128.nc under diagnostics_base_path when prc_typ=='eamxx'.
+vrt_in_file = string(default="")
 
   [[__many__]]
   area_nm = string(default=None)
@@ -159,6 +171,9 @@ input_component = string(default="")
   job_nbr = integer(default=None)
   tpd = integer(default=None)
   input_component = string(default=None)
+  vrt_remap_vars = string(default=None)
+  vrt_remap_file = string(default=None)
+  vrt_in_file = string(default=None)
 
 [e3sm_to_cmip]
 # Metadata json file
@@ -172,6 +187,9 @@ cmip_vars = string(default="")
 input_component = string(default="")
 # TBD: description here
 interp_vars = string(default="U,V,T,Q,RELHUM,OMEGA,Z3")
+# Source vertical coordinate file for ncremap. Required for EAMxx (L128 grid).
+# Defaults to a vert_L128.nc under diagnostics_base_path when prc_typ=='eamxx'.
+vrt_in_file = string(default="")
 
   [[__many__]]
   cmip_metadata = string(default=None)
@@ -179,6 +197,7 @@ interp_vars = string(default="U,V,T,Q,RELHUM,OMEGA,Z3")
   cmip_vars = string(default=None)
   input_component = string(default=None)
   interp_vars = string(default=None)
+  vrt_in_file = string(default=None)
 
 [tc_analysis]
 # NOTE: always overrides value in [default]
diff --git a/zppy/e3sm_diags.py b/zppy/e3sm_diags.py
index a70e51bb..63e18ef6 100644
--- a/zppy/e3sm_diags.py
+++ b/zppy/e3sm_diags.py
@@ -38,6 +38,7 @@ def e3sm_diags(config: ConfigObj, script_dir: str, existing_bundles, job_ids_fil
         dependencies: List[str] = []
         check_parameters_for_bash(c)
         c["scriptDir"] = script_dir
+        c["default_case"] = config["default"]["case"]
         if "ts_num_years" in c.keys():
             c["ts_num_years"] = int(c["ts_num_years"])
         # Loop over year sets
diff --git a/zppy/e3sm_to_cmip.py b/zppy/e3sm_to_cmip.py
index dea48260..1af2b4ab 100644
--- a/zppy/e3sm_to_cmip.py
+++ b/zppy/e3sm_to_cmip.py
@@ -46,6 +46,18 @@ def e3sm_to_cmip(config: ConfigObj, script_dir: str, existing_bundles, job_ids_f
                 default_cmip_plevdata,
                 ParameterInferenceType.PATH_INFERENCE,
             )
+            # EAMxx needs an explicit source vertical grid file (L128);
+            # EAM/CAM have vertical coord info embedded in the file already.
+            if c["prc_typ"] == "eamxx":
+                default_vrt_in_file = (
+                    f"{c['diagnostics_base_path']}/e3sm_to_cmip_data/grids/vert_L128.nc"
+                )
+                set_value_of_parameter_if_undefined(
+                    c,
+                    "vrt_in_file",
+                    default_vrt_in_file,
+                    ParameterInferenceType.PATH_INFERENCE,
+                )
         year_sets: List[Tuple[int, int]] = get_years(c["years"])
         # Loop over year sets
         for s in year_sets:
diff --git a/zppy/templates/climo.bash b/zppy/templates/climo.bash
index 9b0e8e25..a51c256d 100644
--- a/zppy/templates/climo.bash
+++ b/zppy/templates/climo.bash
@@ -20,7 +20,7 @@ cd ${workdir}
 run_nco ncclimo \
 {% if prc_typ == 'eamxx' -%}
 --case={{ case }}.{{ input_files }}.0001-01-01-00000.nc \
---fml_nm={{ case }} \
+--fml_nm={{ fml_nm }} \
 {%- else -%}
 --case={{ case }} \
 {%- endif %}
@@ -97,6 +97,9 @@ fi
 # Now, call ncclimo
 cat input.txt | run_nco ncclimo \
 --case={{ case }}.{{ input_files }} \
+{%- if prc_typ == 'eamxx' %}
+--fml_nm={{ fml_nm }} \
+{%- endif %}
 --jobs=${SLURM_NNODES} \
 --thr=1 \
 {%- if exclude %}
diff --git a/zppy/templates/e3sm_diags.bash b/zppy/templates/e3sm_diags.bash
index e45681bb..76ff49e2 100644
--- a/zppy/templates/e3sm_diags.bash
+++ b/zppy/templates/e3sm_diags.bash
@@ -56,7 +56,8 @@ create_links_climo()
   error_num=$6
   mkdir -p ${climo_dir_destination}
   cd ${climo_dir_destination}
-  cp -s ${climo_dir_source}/${nc_prefix}_*_${begin_year}??_${end_year}??_climo.nc .
+  # Glob covers both EAM monthly (${case}_VAR_*) and EAMxx monthly (${case}.{stream}_VAR_*).
+  cp -s ${climo_dir_source}/${nc_prefix}*_${begin_year}??_${end_year}??_climo.nc .
   if [ $? != 0 ]; then
     cd {{ scriptDir }}
     echo "ERROR (${error_num})" > {{ prefix }}.status
@@ -556,7 +557,7 @@ echo ===== COPY FILES TO WEB SERVER =====
 echo
 
 # Create top-level directory
-web_dir=${www}/${case}/e3sm_diags/{{ sub }}
+web_dir=${www}/{{ default_case }}/e3sm_diags/{{ sub }}
 mkdir -p ${web_dir}
 if [ $? != 0 ]; then
   cd {{ scriptDir }}
diff --git a/zppy/templates/e3sm_to_cmip.bash b/zppy/templates/e3sm_to_cmip.bash
index 092f7273..9bf29421 100644
--- a/zppy/templates/e3sm_to_cmip.bash
+++ b/zppy/templates/e3sm_to_cmip.bash
@@ -33,7 +33,18 @@ EOF
   dest_cmip={{ output }}/post/{{ component }}/{{ ts_grid }}/cmip_ts/{{ frequency }}
   mkdir -p ${dest_cmip}
 
-  {% if input_files.split(".")[0] == 'cam' or input_files.split(".")[0] == 'eam' -%}
+  # If the [ts] task vert-remapped some vars (sibling directory ts_vrt_remap/),
+  # replace the corresponding ts/ symlinks with ts_vrt_remap/ ones. The inline
+  # regrid loop below will detect these (via readlink) and skip them.
+  dest_plev={{ output }}/post/{{ component }}/{{ ts_grid }}/ts_vrt_remap/{{ frequency }}/{{ '%dyr' % (ypf) }}
+  if [ -d "${dest_plev}" ]; then
+    cp -sf ${dest_plev}/*_{{ '%04d' % (yr_start) }}??_{{ '%04d' % (yr_end) }}??.nc $input_dir 2>/dev/null || true
+  fi
+
+  # Gate on prc_typ (atm processing type) rather than fragile input_files
+  # prefix parsing — fixes #820 where input_component="eamxx" with non-eamxx
+  # input_files (e.g., "AVERAGE.nmonths_x1") caused this block to be skipped.
+  {% if prc_typ in ('cam', 'eam', 'eamxx') -%}
   #add code to do vertical interpolation variables at model levels before e3sm_to_cmip
   IFS=',' read -ra mlvars <<< "{{ interp_vars }}"
   for var in "${mlvars[@]}"
@@ -41,8 +52,18 @@ EOF
     for file in ${input_dir}/${var}_{{ '%04d' % (yr_start) }}??_{{ '%04d' % (yr_end) }}??.nc
     do
       if [ -f ${file} ]; then
+        # Skip if file is no longer a symlink — a prior run of this script already
+        # vert-remapped it in place (mv ${file}.plev ${file} replaced the symlink).
+        # Re-running ncremap on the resulting plev file would fail (no lev/ilev dim).
+        if [ ! -L "${file}" ]; then
+          continue
+        fi
+        # Skip if [ts] already vert-remapped this var (symlink points into ts_vrt_remap/)
+        if [[ "$(readlink ${file})" == *ts_vrt_remap* ]]; then
+          continue
+        fi
         #run_nco ncks --rgr xtr_mth=mss_val --vrt_fl='{{cmip_plevdata}}' ${file} ${file}.plev
-        run_nco ncremap {% if machine == 'dane' %}--mpi_pfx='srun -n {{ nodes }}'{% else %}-p mpi{% endif %} --vrt_ntp=log --vrt_xtr=mss_val --vrt_out='{{cmip_plevdata}}' ${file} ${file}.plev
+        run_nco ncremap {% if machine == 'dane' %}--mpi_pfx='srun -n {{ nodes }}'{% else %}-p mpi{% endif %} --vrt_ntp=log --vrt_xtr=mss_val{% if prc_typ == 'eamxx' %} --ps_nm=${file}/ps --vrt_in='{{ vrt_in_file }}'{% endif %} --vrt_out='{{cmip_plevdata}}' ${file} ${file}.plev
         if [ $? != 0 ]; then
           cd {{ scriptDir }}
           echo 'ERROR (1)' > {{ prefix }}.status
diff --git a/zppy/templates/ts.bash b/zppy/templates/ts.bash
index aa517081..e49b9a99 100644
--- a/zppy/templates/ts.bash
+++ b/zppy/templates/ts.bash
@@ -112,6 +112,42 @@ if [ $? != 0 ]; then
   exit 2
 fi
 
+{%- if vrt_remap_vars != '' %}
+
+# Vertical regrid (model levels → pressure levels)
+# When vrt_remap_vars is set, regrid the listed vars and write to a sibling
+# directory ts_vrt_remap/ alongside the standard ts/ output.
+mkdir output_plev
+IFS=',' read -ra vremap_vars <<< "{{ vrt_remap_vars }}"
+for var in "${vremap_vars[@]}"
+do
+  for file in output/${var}_{{ '%04d' % (yr_start) }}??_{{ '%04d' % (yr_end) }}??.nc
+  do
+    if [ ! -f "${file}" ]; then continue; fi
+    out_file=output_plev/$(basename "${file}")
+    run_nco ncremap \
+      {%- if machine == 'dane' %}
+      --mpi_pfx='srun -n {{ nodes }}' \
+      {%- else %}
+      -p mpi \
+      {%- endif %}
+      --vrt_ntp=log \
+      --vrt_xtr=mss_val \
+      --vrt_out='{{ vrt_remap_file }}' \
+      {%- if prc_typ == 'eamxx' %}
+      --ps_nm=${file}/ps \
+      --vrt_in='{{ vrt_in_file }}' \
+      {%- endif %}
+      ${file} ${out_file}
+    if [ $? != 0 ]; then
+      cd {{ scriptDir }}
+      echo 'ERROR (6)' > {{ prefix }}.status
+      exit 6
+    fi
+  done
+done
+{%- endif %}
+
 # Move output ts files to final destination
 {
   dest={{ output }}/post/{{ component }}/{{ grid }}/ts/{{ frequency }}/{{ '%dyr' % (ypf) }}
@@ -124,6 +160,20 @@ if [ $? != 0 ]; then
   exit 3
 fi
 
+{%- if vrt_remap_vars != '' %}
+# Move vertically regridded ts files to sibling destination
+{
+  dest_plev={{ output }}/post/{{ component }}/{{ grid }}/ts_vrt_remap/{{ frequency }}/{{ '%dyr' % (ypf) }}
+  mkdir -p ${dest_plev}
+  mv output_plev/*.nc ${dest_plev}
+}
+if [ $? != 0 ]; then
+  cd {{ scriptDir }}
+  echo 'ERROR (5)' > {{ prefix }}.status
+  exit 5
+fi
+{%- endif %}
+
 # Delete temporary workdir
 cd ..
 if [[ "${debug,,}" != "true" ]]; then
diff --git a/zppy/ts.py b/zppy/ts.py
index 249de9dd..28ebec23 100644
--- a/zppy/ts.py
+++ b/zppy/ts.py
@@ -15,6 +15,7 @@
     set_component_and_prc_typ,
     set_grid,
     set_mapping_file,
+    set_value_of_parameter_if_undefined,
     submit_script,
     write_settings_file,
 )
@@ -35,6 +36,25 @@ def ts(config: ConfigObj, script_dir: str, existing_bundles, job_ids_file):
         set_mapping_file(c)
         set_grid(c)
         set_component_and_prc_typ(c)
+        # Defaults for vertical regrid params (only used when vrt_remap_vars is set)
+        if c["vrt_remap_vars"] != "":
+            default_vrt_remap_file = f"{c['diagnostics_base_path']}/e3sm_to_cmip_data/maps/vrt_remap_plev19.nc"
+            set_value_of_parameter_if_undefined(
+                c,
+                "vrt_remap_file",
+                default_vrt_remap_file,
+                ParameterInferenceType.PATH_INFERENCE,
+            )
+            if c["prc_typ"] == "eamxx":
+                default_vrt_in_file = (
+                    f"{c['diagnostics_base_path']}/e3sm_to_cmip_data/grids/vert_L128.nc"
+                )
+                set_value_of_parameter_if_undefined(
+                    c,
+                    "vrt_in_file",
+                    default_vrt_in_file,
+                    ParameterInferenceType.PATH_INFERENCE,
+                )
         year_sets: List[Tuple[int, int]] = get_years(c["years"])
         # Loop over year sets
         for s in year_sets:
diff --git a/zppy/utils.py b/zppy/utils.py
index da822763..4afff338 100644
--- a/zppy/utils.py
+++ b/zppy/utils.py
@@ -123,6 +123,8 @@ def get_tasks(config: ConfigObj, section_name: str) -> List[Dict[str, Any]]:
         # Merge current section with default. Work with copies to avoid contamination
         task = config["default"].copy()
         task.update(config[section_name].copy())
+        # Preserve top-level case (see comment in the sub-section branch below).
+        task["default_case"] = config["default"]["case"]
         # Set 'subsection' in dictionary to None
         task["subsection"] = None
         # Add to list of tasks if it is active
@@ -141,6 +143,10 @@ def get_tasks(config: ConfigObj, section_name: str) -> List[Dict[str, Any]]:
             sub: Dict[str, Any] = {k: v for k, v in tmp.items() if v is not None}
             # Merge content of sub-secton into section
             task.update(sub)
+            # Preserve top-level case so subsections can still reference it
+            # after their own `case` override has shadowed it (used by climo's
+            # fml_nm composition for EAMxx).
+            task["default_case"] = config["default"]["case"]
             # At this point, task will still include dictionary entries for
             # all sub-sections. Remove them to clean up.
             for s in sub_section_names: