diff --git a/diag_manager/fms_diag_file_object.F90 b/diag_manager/fms_diag_file_object.F90
index f9248a2cf..6a8db1a2d 100644
--- a/diag_manager/fms_diag_file_object.F90
+++ b/diag_manager/fms_diag_file_object.F90
@@ -99,6 +99,7 @@ module fms_diag_file_object_mod
   logical, allocatable :: time_ops !< .True. if file contains variables that are time_min, time_max, time_average,
                                    !! or time_sum
   integer :: unlim_dimension_level !< The unlimited dimension level currently being written
+  integer :: num_time_levels !< The number of time levels that were actually written to the file
   logical :: data_has_been_written !< .True. if data has been written for the current unlimited dimension level
   logical :: is_static !< .True. if the frequency is -1
   integer :: nz_subaxis !< The number of Z axis currently added to the file
@@ -194,6 +195,7 @@ module fms_diag_file_object_mod
   procedure :: init_unlim_dim
   procedure :: update_current_new_file_freq_index
   procedure :: get_unlim_dimension_level
+  procedure :: get_num_time_levels
   procedure :: flush_diag_file
   procedure :: get_next_output
   procedure :: get_next_next_output
@@ -296,6 +298,7 @@ logical function fms_diag_files_object_init (files_array)
      endif
 
      obj%unlim_dimension_level = 0
+     obj%num_time_levels = 0
      obj%is_static = obj%get_file_freq() .eq. -1
      obj%nz_subaxis = 0
 
@@ -1607,6 +1610,16 @@ subroutine init_unlim_dim(this, output_buffers)
   enddo
 end subroutine init_unlim_dim
 
+!> \brief Get the number of time levels that were actually written to the file
+!! \return Number of time levels that were actually written to the file
+pure function get_num_time_levels(this) &
+result(res)
+  class(fmsDiagFileContainer_type), intent(in), target   :: this            !< The file object
+  integer :: res
+
+  res = this%FMS_diag_file%num_time_levels
+end function
+
 !> \brief Get the unlimited dimension level that is in the file
 !! \return The unlimited dimension
 pure function get_unlim_dimension_level(this) &
@@ -1816,6 +1829,13 @@ subroutine close_diag_file(this, output_buffers, model_end_time, diag_fields)
     call close_file(fms2io_fileobj)
   end select
 
+  !< Keep track of the number of time levels that were written to the file
+  !! If the file is using the new_file_freq key, it will be closing the file multiple
+  !! time, so this ensures that we keep a running count
+  !! This is going be written to the output yaml, after all the files are closed
+  this%FMS_diag_file%num_time_levels = this%FMS_diag_file%num_time_levels + &
+                                       this%FMS_diag_file%unlim_dimension_level
+
   !< Reset the unlimited dimension level back to 0, in case the fms2io_fileobj is re-used
   this%FMS_diag_file%unlim_dimension_level = 0
   this%FMS_diag_file%is_file_open = .false.
diff --git a/diag_manager/fms_diag_object.F90 b/diag_manager/fms_diag_object.F90
index 9bb7ef308..e1fb0a1b5 100644
--- a/diag_manager/fms_diag_object.F90
+++ b/diag_manager/fms_diag_object.F90
@@ -99,6 +99,7 @@ module fms_diag_object_mod
     procedure :: allocate_diag_field_output_buffers
     procedure :: fms_diag_compare_window
     procedure :: set_time_end
+    procedure :: get_ntimes_per_file
 #ifdef use_yaml
     procedure :: get_diag_buffer
 #endif
@@ -154,6 +155,28 @@ subroutine fms_diag_object_init (this,diag_subset_output, time_init)
 #endif
 end subroutine fms_diag_object_init
 
+!> @brief Determines the number of time levels that were written each file
+!! @return The number of time levels that were written each file
+function get_ntimes_per_file(this) &
+  result(ntimes)
+  class(fmsDiagObject_type) :: this !< Diag object
+  integer, allocatable :: ntimes(:)
+
+  integer :: i !< For looping through the files
+
+#ifdef use_yaml
+  allocate(ntimes(size(this%FMS_diag_files)))
+  do i = 1, size(this%FMS_diag_files)
+    ntimes(i) = this%FMS_diag_files(i)%get_num_time_levels()
+  enddo
+#else
+  allocate(ntimes(1))
+  ntimes = diag_null
+  call mpp_error(FATAL, "You must compile with -Duse_yaml to call fms_diag_object%get_ntimes_per_file!")
+#endif
+
+end function get_ntimes_per_file
+
 !> \description Loops through all files and does one final write.
 !! Closes all files
 !! Deallocates all buffers, fields, and files
@@ -161,17 +184,20 @@ end subroutine fms_diag_object_init
 subroutine fms_diag_object_end (this, time)
   class(fmsDiagObject_type) :: this
   TYPE(time_type), INTENT(in) :: time
+  integer, allocatable :: ntimes(:) !< Number of time steps per file
 
   integer                   :: i
 #ifdef use_yaml
   !TODO: loop through files and force write
   if (.not. this%initialized) return
 
-  ! write output yaml
-  call fms_diag_yaml_out()
-
   call this%do_buffer_math()
   call this%fms_diag_do_io(end_time=time)
+
+  ! write output yaml
+  ntimes = this%get_ntimes_per_file()
+  call fms_diag_yaml_out(ntimes)
+
   !TODO: Deallocate diag object arrays and clean up all memory
   do i=1, size(this%FMS_diag_output_buffers)
     call this%FMS_diag_output_buffers(i)%flush_buffer()
diff --git a/diag_manager/fms_diag_yaml.F90 b/diag_manager/fms_diag_yaml.F90
index 4d40b06d0..4c36e733e 100644
--- a/diag_manager/fms_diag_yaml.F90
+++ b/diag_manager/fms_diag_yaml.F90
@@ -1645,7 +1645,8 @@ subroutine dump_diag_yaml_obj( filename )
 !> Writes an output yaml with all available information on the written files.
 !! Will only write with root pe.
 !! Global attributes are limited to 16 per file.
-subroutine fms_diag_yaml_out()
+subroutine fms_diag_yaml_out(ntimes)
+  integer, intent(in) :: ntimes(:) !< The number of time levels that were written for each file
   type(diagYamlFiles_type), pointer :: fileptr !< pointer for individual variables
   type(diagYamlFilesVar_type), pointer :: varptr !< pointer for individual variables
   type (fmsyamloutkeys_type), allocatable :: keys(:), keys2(:), keys3(:)
@@ -1714,6 +1715,7 @@ subroutine fms_diag_yaml_out()
     call fms_f2c_string(keys2(i)%key8, 'start_time')
     call fms_f2c_string(keys2(i)%key9, 'file_duration')
     call fms_f2c_string(keys2(i)%key10, 'file_duration_units')
+    call fms_f2c_string(keys2(i)%key11, 'number_of_timelevels')
 
     call fms_f2c_string(vals2(i)%val1, fileptr%file_fname)
     call fms_f2c_string(vals2(i)%val5, fileptr%file_unlimdim)
@@ -1750,6 +1752,7 @@ subroutine fms_diag_yaml_out()
     enddo
     call fms_f2c_string(vals2(i)%val9, adjustl(tmpstr1))
     call fms_f2c_string(vals2(i)%val10, get_diag_unit_string(fileptr%file_duration_units))
+    call fms_f2c_string(vals2(i)%val11, string(ntimes(i)))
 
     !! tier 3 - varlists, subregion, global metadata
     call yaml_out_add_level2key('varlist', keys2(i))
diff --git a/test_fms/diag_manager/test_diag_manager2.sh b/test_fms/diag_manager/test_diag_manager2.sh
index 1c54a5496..948bf7794 100755
--- a/test_fms/diag_manager/test_diag_manager2.sh
+++ b/test_fms/diag_manager/test_diag_manager2.sh
@@ -898,6 +898,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 1
   varlist:
   - module: atm_mod
     var_name: var7
@@ -930,6 +931,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: ocn_mod
     var_name: var1
@@ -972,6 +974,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: atm_mod
     var_name: var3
@@ -1036,6 +1039,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: lnd_mod
     var_name: var5
@@ -1078,6 +1082,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: lnd_mod
     var_name: var1
@@ -1109,6 +1114,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: atm_mod
     var_name: var4
@@ -1140,6 +1146,7 @@ diag_files:
   start_time: 00020101.000000
   file_duration: 12
   file_duration_units: hours
+  number_of_timelevels: 2
   varlist:
   - module: ocn_mod
     var_name: var1
@@ -1171,6 +1178,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 3
   varlist:
   - module: ocn_mod
     var_name: var1
@@ -1202,6 +1210,7 @@ diag_files:
   start_time: 00020101.000000
   file_duration: 12 3 9
   file_duration_units: hours hours hours
+  number_of_timelevels: 24
   varlist:
   - module: ocn_mod
     var_name: var1
@@ -1233,6 +1242,7 @@ diag_files:
   start_time: 00020101.000000
   file_duration: 12 3 9
   file_duration_units: hours hours hours
+  number_of_timelevels: 24
   varlist:
   - module: ocn_mod
     var_name: var1
@@ -1264,6 +1274,7 @@ diag_files:
   start_time:
   file_duration:
   file_duration_units:
+  number_of_timelevels: 1
   varlist:
   - module: ocn_mod
     var_name: var1