diff --git a/src/control/cam_comp.F90 b/src/control/cam_comp.F90
index 85edc36c..4b677288 100644
--- a/src/control/cam_comp.F90
+++ b/src/control/cam_comp.F90
@@ -455,7 +455,7 @@ end subroutine cam_run4
    !
    !-----------------------------------------------------------------------
    !
-   subroutine cam_timestep_final()
+   subroutine cam_timestep_final(do_ncdata_check)
       !-----------------------------------------------------------------------
       !
       ! Purpose:   Timestep final runs at the end of each timestep
@@ -464,12 +464,15 @@ subroutine cam_timestep_final()
 
       use phys_comp, only: phys_timestep_final
 
+      !Flag for whether a snapshot (ncdata) check should be run or not
+      logical, intent(in) :: do_ncdata_check
+
       !
       !----------------------------------------------------------
       ! PHYS_TIMESTEP_FINAL Call the Physics package
       !----------------------------------------------------------
       !
-      call phys_timestep_final()
+      call phys_timestep_final(do_ncdata_check)
 
    end subroutine cam_timestep_final
 
diff --git a/src/cpl/nuopc/atm_comp_nuopc.F90 b/src/cpl/nuopc/atm_comp_nuopc.F90
index 818760eb..7cdd1247 100644
--- a/src/cpl/nuopc/atm_comp_nuopc.F90
+++ b/src/cpl/nuopc/atm_comp_nuopc.F90
@@ -1049,6 +1049,7 @@ subroutine ModelAdvance(gcomp, rc)
     integer                 :: lbnum
     integer                 :: localPet, localPeCount
     logical                 :: first_time = .true.
+    logical                 :: do_ncdata_check  !Flag notifying SIMA if it is OK to perform a snapshot check
     character(len=*),parameter  :: subname=trim(modName)//':(ModelAdvance) '
     !-------------------------------------------------------------------------------
 
@@ -1117,6 +1118,7 @@ subroutine ModelAdvance(gcomp, rc)
     end if
 
     dosend = .false.
+    do_ncdata_check = .false.
     do while (.not. dosend)
 
        ! TODO: This is currently hard-wired - is there a better way for nuopc?
@@ -1124,6 +1126,7 @@ subroutine ModelAdvance(gcomp, rc)
        ! Note that the model clock is updated at the end of the time step not at the beginning
        if (get_nstep() > 0) then
           dosend = .true.
+          do_ncdata_check = .true.
        end if
 
        ! Determine if time to write restart
@@ -1152,6 +1155,7 @@ subroutine ModelAdvance(gcomp, rc)
        endif
 
        ! Run CAM (run2, run3, run4)
+       ! This includes the "physics_after_coupler" CCPP physics group.
 
        call t_startf ('CAM_run2')
        call cam_run2( cam_out, cam_in )
@@ -1165,7 +1169,7 @@ subroutine ModelAdvance(gcomp, rc)
        call cam_run4( cam_out, cam_in, rstwr, nlend, &
             yr_spec=yr_sync, mon_spec=mon_sync, day_spec=day_sync, sec_spec=tod_sync)
        call t_stopf  ('CAM_run4')
-       call cam_timestep_final()
+       call cam_timestep_final(do_ncdata_check=do_ncdata_check)
 
        ! Advance cam time step
 
@@ -1174,7 +1178,8 @@ subroutine ModelAdvance(gcomp, rc)
        call t_stopf  ('CAM_adv_timestep')
        call cam_timestep_init()
 
-       ! Run cam radiation/clouds (run1)
+       ! Run CAM (run1)
+       ! This includes the "physics_before_coupler" CCPP physics group.
 
        call t_startf ('CAM_run1')
        call cam_run1 ( cam_in, cam_out )
@@ -1401,11 +1406,11 @@ subroutine ModelFinalize(gcomp, rc)
 
     rc = ESMF_SUCCESS
 
-    call shr_log_getLogUnit (shrlogunit)
-    call shr_log_setLogUnit (iulog)
+    call shr_log_getLogUnit(shrlogunit)
+    call shr_log_setLogUnit(iulog)
 
-    call cam_timestep_final()
-    call cam_final( cam_out, cam_in )
+    call cam_timestep_final(do_ncdata_check=.false.)
+    call cam_final(cam_out, cam_in)
 
     if (masterproc) then
        write(iulog,F91)
diff --git a/src/data/registry.xml b/src/data/registry.xml
index c9dd29e7..3d8b5bc0 100644
--- a/src/data/registry.xml
+++ b/src/data/registry.xml
@@ -313,12 +313,18 @@
               phys_timestep_init_zero="true">
       <long_name>Total tendency from physics suite</long_name>
     </variable>
-    <!-- Physics timestep -->
+    <!-- Timestep variables -->
     <variable local_name="dtime_phys"
               standard_name="timestep_for_physics"
               units="s" type="real" kind="kind_phys">
       <long_name>timestep for physics</long_name>
     </variable>
+    <variable local_name="nstep"
+              standard_name="current_timestep_number"
+              units="count" type="integer">
+      <long_name>current timestep number</long_name>
+      <initial_value>0</initial_value>
+    </variable>
     <!-- Error handling variables -->
     <variable local_name="errcode"
               standard_name="ccpp_error_code"
diff --git a/src/physics/utils/phys_comp.F90 b/src/physics/utils/phys_comp.F90
index c3e91bf9..abe0428a 100644
--- a/src/physics/utils/phys_comp.F90
+++ b/src/physics/utils/phys_comp.F90
@@ -185,11 +185,9 @@ subroutine phys_timestep_init()
       ! Physics needs to read in all data not read in by the dycore
       ncdata => initial_file_get_id()
 
-      ! data_frame is the next input frame for physics input fields
-      ! Frame 1 is skipped for snapshot files
-      !!XXgoldyXX: This section needs to have better logic once we know if
-      !!           this is a physics test bench run.
-      data_frame = get_nstep() + 2
+      ! data_frame is the next input frame for
+      ! physics fields that must be read from a file:
+      data_frame = get_nstep()
 
       ! Initialize host model variables that must be done each time step:
       call physics_types_tstep_init()
@@ -237,15 +235,18 @@ subroutine phys_run2()
 
    end subroutine phys_run2
 
-   subroutine phys_timestep_final()
+   subroutine phys_timestep_final(do_ncdata_check)
       use time_manager,   only: get_nstep
       use cam_abortutils, only: endrun
       use cam_initfiles,  only: unset_path_str
       use cam_ccpp_cap,   only: cam_ccpp_physics_timestep_final
       use physics_inputs, only: physics_check_data
 
+      ! Subroutine inputs
+      logical, intent(in) :: do_ncdata_check
+
       ! Local variables
-      integer                              :: data_frame
+      integer             :: data_frame
 
       ! Finalize the time step
       call cam_ccpp_physics_timestep_final(phys_suite_name)
@@ -253,16 +254,16 @@ subroutine phys_timestep_final()
          call endrun('cam_ccpp_physics_timestep_final: '//trim(errmsg))
       end if
 
-      ! data_frame is the next input frame for physics input fields
-      ! Frame 1 is skipped for snapshot files
-      !!XXgoldyXX: This section needs to have better logic once we know if
-      !!           this is a physics test bench run.
-      data_frame = get_nstep() + 2
+      ! data_frame is the next input frame for
+      ! physics snapshot validation fields
+      data_frame = get_nstep()
 
       ! Determine if physics_check should be run:
       if (trim(ncdata_check) /= trim(unset_path_str)) then
-         call physics_check_data(ncdata_check, suite_names, data_frame,       &
-            min_difference, min_relative_value)
+         if (do_ncdata_check) then
+            call physics_check_data(ncdata_check, suite_names, data_frame,  &
+                                    min_difference, min_relative_value)
+         end if
       end if
 
    end subroutine phys_timestep_final
diff --git a/src/utils/time_manager.F90 b/src/utils/time_manager.F90
index 91114ccd..803a47e9 100644
--- a/src/utils/time_manager.F90
+++ b/src/utils/time_manager.F90
@@ -520,6 +520,13 @@ subroutine advance_timestep()
 
 ! Increment the timestep number.
 
+! Use statements
+   use ESMF,          only: ESMF_ClockAdvance
+   use cam_logfile,   only: iulog
+   use physics_types, only: nstep
+   use spmd_utils,    only: masterproc
+   use string_utils,  only: stringify
+
 ! Local variables
    character(len=*), parameter :: sub = 'advance_timestep'
    integer :: rc
@@ -528,6 +535,17 @@ subroutine advance_timestep()
    call ESMF_ClockAdvance( tm_clock, rc=rc )
    call chkrc(rc, sub//': error return from ESMF_ClockAdvance')
 
+! Set current timestep number for use in CCPP physics schemes:
+   nstep = get_nstep()
+
+! Write new timestep to CAM log file.
+
+   if (masterproc) then
+      write(iulog,*) '------------------------'
+      write(iulog,*) 'CAM-SIMA time step advanced (nstep = '//stringify([nstep])//')'
+      write(iulog,*) '------------------------'
+   end if
+
 ! Set first step flag off.
 
    tm_first_restart_step = .false.