diff --git a/diag_manager/fms_diag_field_object.F90 b/diag_manager/fms_diag_field_object.F90
index 58b830d36c..1eb0221e94 100644
--- a/diag_manager/fms_diag_field_object.F90
+++ b/diag_manager/fms_diag_field_object.F90
@@ -96,6 +96,7 @@ module fms_diag_field_object_mod
      procedure :: set_math_needs_to_be_done => set_math_needs_to_be_done
      procedure :: add_attribute => diag_field_add_attribute
      procedure :: vartype_inq => what_is_vartype
+     procedure :: set_mask_variant
 ! Check functions
      procedure :: is_static => diag_obj_is_static
      procedure :: is_scalar
@@ -436,6 +437,14 @@ subroutine set_math_needs_to_be_done (this, math_needs_to_be_done)
   this%math_needs_to_be_done = math_needs_to_be_done
 end subroutine set_math_needs_to_be_done
 
+!> @brief Set the mask_variant to .true.
+subroutine set_mask_variant(this, is_masked)
+  class (fmsDiagField_type) , intent(inout):: this      !< The diag field object
+  logical,                    intent (in)  :: is_masked !< .True. if the field is masked
+
+  this%mask_variant = is_masked
+end subroutine set_mask_variant
+
 !> @brief Sets the flag saying that the data buffer is allocated
 subroutine set_data_buffer_is_allocated (this, data_buffer_is_allocated)
   class (fmsDiagField_type) , intent(inout) :: this                     !< The field object
diff --git a/diag_manager/fms_diag_object.F90 b/diag_manager/fms_diag_object.F90
index d846c97afa..10c8514479 100644
--- a/diag_manager/fms_diag_object.F90
+++ b/diag_manager/fms_diag_object.F90
@@ -554,6 +554,9 @@ logical function fms_diag_accept_data (this, diag_field_id, field_data, mask, rm
     if (.not. allocated(mask) .and. .not. allocated(rmask)) call mpp_error(FATAL, &
       "The field was registered with mask_variant, but mask or rmask are not present in the send_data call. "//&
       trim(field_info))
+  else
+    if (allocated(mask) .or. allocated(rmask)) &
+      call this%FMS_diag_fields(diag_field_id)%set_mask_variant(.True.)
   endif
 
   !< Check that mask and rmask are not both present
@@ -795,6 +798,14 @@ function fms_diag_do_reduction(this, field_data, diag_field_id, oor_mask, weight
       call mpp_error(FATAl, "The missing value for the field:"//trim(field_ptr%get_varname())//&
         &" was not allocated to the correct type. This shouldn't have happened")
     end select
+  else
+    select type (missing_val => get_default_missing_value(r8))
+    type is (real(kind=r8_kind))
+      missing_value = missing_val
+    class default
+      call mpp_error(FATAl, "The missing value for the field:"//trim(field_ptr%get_varname())//&
+        &" was not allocated to the correct type. This shouldn't have happened")
+    end select
   endif
 
   buffer_loop: do ids = 1, size(field_ptr%buffer_ids)
@@ -870,12 +881,23 @@ function fms_diag_do_reduction(this, field_data, diag_field_id, oor_mask, weight
     reduction_method = field_yaml_ptr%get_var_reduction()
     select case(reduction_method)
     case (time_none)
-      error_msg = buffer_ptr%do_time_none_wrapper(field_data, oor_mask, bounds_in, bounds_out, missing_value)
+      error_msg = buffer_ptr%do_time_none_wrapper(field_data, oor_mask, field_ptr%get_mask_variant(), &
+        bounds_in, bounds_out, missing_value)
       if (trim(error_msg) .ne. "") then
         return
       endif
     case (time_min)
+      error_msg = buffer_ptr%do_time_min_wrapper(field_data, oor_mask, field_ptr%get_mask_variant(), &
+        bounds_in, bounds_out, missing_value)
+      if (trim(error_msg) .ne. "") then
+        return
+      endif
     case (time_max)
+      error_msg = buffer_ptr%do_time_max_wrapper(field_data, oor_mask, field_ptr%get_mask_variant(), &
+        bounds_in, bounds_out, missing_value)
+      if (trim(error_msg) .ne. "") then
+        return
+      endif
     case (time_sum)
     case (time_average)
     case (time_power)
diff --git a/diag_manager/fms_diag_output_buffer.F90 b/diag_manager/fms_diag_output_buffer.F90
index 9a3ffdf469..b2c54f1387 100644
--- a/diag_manager/fms_diag_output_buffer.F90
+++ b/diag_manager/fms_diag_output_buffer.F90
@@ -34,7 +34,7 @@ module fms_diag_output_buffer_mod
 use fms2_io_mod, only: FmsNetcdfFile_t, write_data, FmsNetcdfDomainFile_t, FmsNetcdfUnstructuredDomainFile_t
 use fms_diag_yaml_mod, only: diag_yaml
 use fms_diag_bbox_mod, only: fmsDiagIbounds_type
-use fms_diag_reduction_methods_mod, only: do_time_none
+use fms_diag_reduction_methods_mod, only: do_time_none, do_time_min, do_time_max
 use fms_diag_time_utils_mod, only: diag_time_inc
 
 implicit none
@@ -76,6 +76,8 @@ module fms_diag_output_buffer_mod
   procedure :: get_buffer
   procedure :: flush_buffer
   procedure :: do_time_none_wrapper
+  procedure :: do_time_min_wrapper
+  procedure :: do_time_max_wrapper
 
 end type fmsDiagOutputBuffer_type
 
@@ -470,35 +472,104 @@ end subroutine write_buffer_wrapper_u
 
 !> @brief Does the time_none reduction method on the buffer object
 !! @return Error message if the math was not successful
-function do_time_none_wrapper(this, field_data, mask, bounds_in, bounds_out, missing_value) &
+function do_time_none_wrapper(this, field_data, mask, is_masked, bounds_in, bounds_out, missing_value) &
   result(err_msg)
   class(fmsDiagOutputBuffer_type), intent(inout) :: this                !< buffer object to write
   class(*),                        intent(in)    :: field_data(:,:,:,:) !< Buffer data for current time
   type(fmsDiagIbounds_type),       intent(in)    :: bounds_in           !< Indicies for the buffer passed in
   type(fmsDiagIbounds_type),       intent(in)    :: bounds_out          !< Indicies for the output buffer
   logical,                         intent(in)    :: mask(:,:,:,:)       !< Mask for the field
+  logical,                         intent(in)    :: is_masked           !< .True. if the field has a mask
   real(kind=r8_kind),              intent(in)    :: missing_value       !< Missing_value for data points that are masked
   character(len=50) :: err_msg
 
-  !TODO This does not need to be done for every time step
   !TODO This will be expanded for integers
   err_msg = ""
   select type (output_buffer => this%buffer)
     type is (real(kind=r8_kind))
       select type (field_data)
       type is (real(kind=r8_kind))
-        call do_time_none(output_buffer, field_data, mask, bounds_in, bounds_out, missing_value)
+        call do_time_none(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, missing_value)
       class default
-        err_msg="the output buffer and the buffer send in are not of the same type (r8_kind)"
+        err_msg="do_time_none_wrapper::the output buffer and the buffer send in are not of the same type (r8_kind)"
       end select
     type is (real(kind=r4_kind))
       select type (field_data)
       type is (real(kind=r4_kind))
-        call do_time_none(output_buffer, field_data, mask, bounds_in, bounds_out, real(missing_value, kind=r4_kind))
+        call do_time_none(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, &
+          real(missing_value, kind=r4_kind))
       class default
-        err_msg="the output buffer and the buffer send in are not of the same type (r4_kind)"
+        err_msg="do_time_none_wrapper::the output buffer and the buffer send in are not of the same type (r4_kind)"
       end select
   end select
 end function do_time_none_wrapper
+
+!> @brief Does the time_min reduction method on the buffer object
+!! @return Error message if the math was not successful
+function do_time_min_wrapper(this, field_data, mask, is_masked, bounds_in, bounds_out, missing_value) &
+  result(err_msg)
+  class(fmsDiagOutputBuffer_type), intent(inout) :: this                !< buffer object to write
+  class(*),                        intent(in)    :: field_data(:,:,:,:) !< Buffer data for current time
+  type(fmsDiagIbounds_type),       intent(in)    :: bounds_in           !< Indicies for the buffer passed in
+  type(fmsDiagIbounds_type),       intent(in)    :: bounds_out          !< Indicies for the output buffer
+  logical,                         intent(in)    :: mask(:,:,:,:)       !< Mask for the field
+  logical,                         intent(in)    :: is_masked           !< .True. if the field has a mask
+  real(kind=r8_kind),              intent(in)    :: missing_value       !< Missing_value for data points that are masked
+  character(len=50) :: err_msg
+
+  !TODO This will be expanded for integers
+  err_msg = ""
+  select type (output_buffer => this%buffer)
+    type is (real(kind=r8_kind))
+      select type (field_data)
+      type is (real(kind=r8_kind))
+        call do_time_min(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, missing_value)
+      class default
+        err_msg="do_time_min_wrapper::the output buffer and the buffer send in are not of the same type (r8_kind)"
+      end select
+    type is (real(kind=r4_kind))
+      select type (field_data)
+      type is (real(kind=r4_kind))
+        call do_time_min(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, &
+          real(missing_value, kind=r4_kind))
+      class default
+        err_msg="do_time_min_wrapper::the output buffer and the buffer send in are not of the same type (r4_kind)"
+      end select
+  end select
+end function do_time_min_wrapper
+
+!> @brief Does the time_min reduction method on the buffer object
+!! @return Error message if the math was not successful
+function do_time_max_wrapper(this, field_data, mask, is_masked, bounds_in, bounds_out, missing_value) &
+  result(err_msg)
+  class(fmsDiagOutputBuffer_type), intent(inout) :: this                !< buffer object to write
+  class(*),                        intent(in)    :: field_data(:,:,:,:) !< Buffer data for current time
+  type(fmsDiagIbounds_type),       intent(in)    :: bounds_in           !< Indicies for the buffer passed in
+  type(fmsDiagIbounds_type),       intent(in)    :: bounds_out          !< Indicies for the output buffer
+  logical,                         intent(in)    :: mask(:,:,:,:)       !< Mask for the field
+  logical,                         intent(in)    :: is_masked           !< .True. if the field has a mask
+  real(kind=r8_kind),              intent(in)    :: missing_value       !< Missing_value for data points that are masked
+  character(len=50) :: err_msg
+
+  !TODO This will be expanded for integers
+  err_msg = ""
+  select type (output_buffer => this%buffer)
+    type is (real(kind=r8_kind))
+      select type (field_data)
+      type is (real(kind=r8_kind))
+        call do_time_max(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, missing_value)
+      class default
+        err_msg="do_time_max_wrapper::the output buffer and the buffer send in are not of the same type (r8_kind)"
+      end select
+    type is (real(kind=r4_kind))
+      select type (field_data)
+      type is (real(kind=r4_kind))
+        call do_time_max(output_buffer, field_data, mask, is_masked, bounds_in, bounds_out, &
+          real(missing_value, kind=r4_kind))
+      class default
+        err_msg="do_time_max_wrapper::the output buffer and the buffer send in are not of the same type (r4_kind)"
+      end select
+  end select
+end function do_time_max_wrapper
 #endif
 end module fms_diag_output_buffer_mod
diff --git a/diag_manager/fms_diag_reduction_methods.F90 b/diag_manager/fms_diag_reduction_methods.F90
index fa4a7b9fcd..c48f9b21cd 100644
--- a/diag_manager/fms_diag_reduction_methods.F90
+++ b/diag_manager/fms_diag_reduction_methods.F90
@@ -35,7 +35,7 @@ module fms_diag_reduction_methods_mod
   private
 
   public :: check_indices_order, init_mask, set_weight
-  public :: do_time_none
+  public :: do_time_none, do_time_min, do_time_max
 
   !> @brief Does the time_none reduction method. See include/fms_diag_reduction_methods.inc
   !TODO This needs to be extended to integers
@@ -43,6 +43,18 @@ module fms_diag_reduction_methods_mod
     module procedure do_time_none_r4, do_time_none_r8
   end interface do_time_none
 
+  !> @brief Does the time_min reduction method. See include/fms_diag_reduction_methods.inc
+  !TODO This needs to be extended to integers
+  interface do_time_min
+    module procedure do_time_min_r4, do_time_min_r8
+  end interface do_time_min
+
+  !> @brief Does the time_max reduction method. See include/fms_diag_reduction_methods.inc
+  !TODO This needs to be extended to integers
+  interface do_time_max
+    module procedure do_time_max_r4, do_time_max_r8
+  end interface do_time_max
+
   contains
 
   !> @brief Checks improper combinations of is, ie, js, and je.
diff --git a/diag_manager/include/fms_diag_reduction_methods.inc b/diag_manager/include/fms_diag_reduction_methods.inc
index ddb6b8c926..72332d650e 100644
--- a/diag_manager/include/fms_diag_reduction_methods.inc
+++ b/diag_manager/include/fms_diag_reduction_methods.inc
@@ -18,10 +18,11 @@
 !***********************************************************************
 
 !> @brief Do the time_none reduction method (i.e copy the correct portion of the input data)
-subroutine DO_TIME_NONE_ (data_out, data_in, mask, bounds_in, bounds_out, missing_value)
+subroutine DO_TIME_NONE_ (data_out, data_in, mask, is_masked, bounds_in, bounds_out, missing_value)
   real(FMS_TRM_KIND_),       intent(inout) :: data_out(:,:,:,:,:) !< output data
   real(FMS_TRM_KIND_),       intent(in)    :: data_in(:,:,:,:)    !< data to update the buffer with
   logical,                   intent(in)    :: mask(:,:,:,:)       !< mask
+  logical,                   intent(in)    :: is_masked           !< .True. if the field is using a mask
   type(fmsDiagIbounds_type), intent(in)    :: bounds_in           !< indices indicating the correct portion
                                                                   !! of the input buffer
   type(fmsDiagIbounds_type), intent(in)    :: bounds_out          !< indices indicating the correct portion
@@ -47,11 +48,157 @@ subroutine DO_TIME_NONE_ (data_out, data_in, mask, bounds_in, bounds_out, missin
   ks_in = bounds_in%get_kmin()
   ke_in = bounds_in%get_kmax()
 
-  where (mask(is_in:ie_in, js_in:je_in, ks_in:ke_in, :))
+  if (is_masked) then
+    where (mask(is_in:ie_in, js_in:je_in, ks_in:ke_in, :))
+      data_out(is_out:ie_out, js_out:je_out, ks_out:ke_out, :, 1) = &
+      data_in(is_in:ie_in, js_in:je_in, ks_in:ke_in, :)
+    elsewhere
+      data_out(is_out:ie_out, js_out:je_out, ks_out:ke_out, :, 1) = missing_value
+    end where
+  else
     data_out(is_out:ie_out, js_out:je_out, ks_out:ke_out, :, 1) = &
-    data_in(is_in:ie_in, js_in:je_in, ks_in:ke_in, :)
-  elsewhere
-    data_out(is_out:ie_out, js_out:je_out, ks_out:ke_out, :, 1) = missing_value
-  end where
+      data_in(is_in:ie_in, js_in:je_in, ks_in:ke_in, :)
+  endif
 
-end subroutine DO_TIME_NONE_
\ No newline at end of file
+end subroutine DO_TIME_NONE_
+
+!> @brief Do the time_min reduction method (i.e maintain the minimum value of the averaging time)
+subroutine DO_TIME_MIN_ (data_out, data_in, mask, is_masked, bounds_in, bounds_out, missing_value)
+  real(FMS_TRM_KIND_),       intent(inout) :: data_out(:,:,:,:,:) !< output data
+  real(FMS_TRM_KIND_),       intent(in)    :: data_in(:,:,:,:)    !< data to update the buffer with
+  logical,                   intent(in)    :: mask(:,:,:,:)       !< mask
+  logical,                   intent(in)    :: is_masked           !< .True. if the field is using a mask
+  type(fmsDiagIbounds_type), intent(in)    :: bounds_in           !< indices indicating the correct portion
+                                                                  !! of the input buffer
+  type(fmsDiagIbounds_type), intent(in)    :: bounds_out          !< indices indicating the correct portion
+                                                                  !! of the output buffer
+  real(FMS_TRM_KIND_),       intent(in)    :: missing_value       !< Missing_value for data points that are masked
+
+  integer :: is_in, ie_in, js_in, je_in, ks_in, ke_in       !< Starting and ending indices of each dimention for
+                                                            !! the input buffer
+  integer :: is_out, ie_out, js_out, je_out, ks_out, ke_out !< Starting and ending indices of each dimention for
+                                                            !! the output buffer
+
+  integer :: i, j, k, l !< For looping
+
+  is_out = bounds_out%get_imin()
+  ie_out = bounds_out%get_imax()
+  js_out = bounds_out%get_jmin()
+  je_out = bounds_out%get_jmax()
+  ks_out = bounds_out%get_kmin()
+  ke_out = bounds_out%get_kmax()
+
+  is_in = bounds_in%get_imin()
+  ie_in = bounds_in%get_imax()
+  js_in = bounds_in%get_jmin()
+  je_in = bounds_in%get_jmax()
+  ks_in = bounds_in%get_kmin()
+  ke_in = bounds_in%get_kmax()
+
+  !> Seperated this loops for performance. If is_masked = .false. (i.e "mask" and "rmask" were never passed in)
+  !! then mask will always be .True. so the if (mask) is redudant.
+  if (is_masked) then
+    do l = 0, size(data_out, 4) - 1
+      do k = 0, ke_out - ks_out
+        do j = 0, je_out - js_out
+          do i = 0, ie_out - is_out
+            if (mask(is_in + i, js_in + j, ks_in + k, l + 1)) then
+              if (data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) .gt. &
+                data_in(is_in + i, js_in + j, ks_in + k, l + 1) ) then
+                  data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = &
+                    data_in(is_in +i, js_in + j, ks_in + k, l + 1)
+              endif
+            else
+              data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = missing_value
+            endif
+          enddo
+        enddo
+      enddo
+    enddo
+  else
+    do l = 0, size(data_out, 4) - 1
+      do k = 0, ke_out - ks_out
+        do j = 0, je_out - js_out
+          do i = 0, ie_out - is_out
+            if (data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) .gt. &
+              data_in(is_in + i, js_in + j, ks_in + k, l + 1) ) then
+                data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = &
+                  data_in(is_in +i, js_in + j, ks_in + k, l + 1)
+            endif
+          enddo
+        enddo
+      enddo
+    enddo
+  endif
+
+end subroutine DO_TIME_MIN_
+
+!> @brief Do the time_max reduction method (i.e maintain the maximum value of the averaging time)
+subroutine DO_TIME_MAX_ (data_out, data_in, mask, is_masked, bounds_in, bounds_out, missing_value)
+  real(FMS_TRM_KIND_),       intent(inout) :: data_out(:,:,:,:,:) !< output data
+  real(FMS_TRM_KIND_),       intent(in)    :: data_in(:,:,:,:)    !< data to update the buffer with
+  logical,                   intent(in)    :: mask(:,:,:,:)       !< mask
+  logical,                   intent(in)    :: is_masked           !< .True. if the field is using a mask
+  type(fmsDiagIbounds_type), intent(in)    :: bounds_in           !< indices indicating the correct portion
+                                                                  !! of the input buffer
+  type(fmsDiagIbounds_type), intent(in)    :: bounds_out          !< indices indicating the correct portion
+                                                                  !! of the output buffer
+  real(FMS_TRM_KIND_),       intent(in)    :: missing_value       !< Missing_value for data points that are masked
+
+  integer :: is_in, ie_in, js_in, je_in, ks_in, ke_in       !< Starting and ending indices of each dimention for
+                                                            !! the input buffer
+  integer :: is_out, ie_out, js_out, je_out, ks_out, ke_out !< Starting and ending indices of each dimention for
+                                                            !! the output buffer
+
+  integer :: i, j, k, l !< For looping
+
+  is_out = bounds_out%get_imin()
+  ie_out = bounds_out%get_imax()
+  js_out = bounds_out%get_jmin()
+  je_out = bounds_out%get_jmax()
+  ks_out = bounds_out%get_kmin()
+  ke_out = bounds_out%get_kmax()
+
+  is_in = bounds_in%get_imin()
+  ie_in = bounds_in%get_imax()
+  js_in = bounds_in%get_jmin()
+  je_in = bounds_in%get_jmax()
+  ks_in = bounds_in%get_kmin()
+  ke_in = bounds_in%get_kmax()
+
+  !> Seperated this loops for performance. If is_masked = .false. (i.e "mask" and "rmask" were never passed in)
+  !! then mask will always be .True. so the if (mask) is redudant.
+  if (is_masked) then
+    do l = 0, size(data_out, 4) - 1
+      do k = 0, ke_out - ks_out
+        do j = 0, je_out - js_out
+          do i = 0, ie_out - is_out
+            if (mask(is_in + i, js_in + j, ks_in + k, l + 1)) then
+              if (data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) .lt. &
+                data_in(is_in + i, js_in + j, ks_in + k, l + 1) ) then
+                  data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = &
+                    data_in(is_in +i, js_in + j, ks_in + k, l + 1)
+              endif
+            else
+              data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = missing_value
+            endif
+          enddo
+        enddo
+      enddo
+    enddo
+  else
+    do l = 0, size(data_out, 4) - 1
+      do k = 0, ke_out - ks_out
+        do j = 0, je_out - js_out
+          do i = 0, ie_out - is_out
+            if (data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) .lt. &
+              data_in(is_in + i, js_in + j, ks_in + k, l + 1) ) then
+                data_out(is_out + i, js_out + j, ks_out + k, l + 1, 1) = &
+                  data_in(is_in +i, js_in + j, ks_in + k, l + 1)
+            endif
+          enddo
+        enddo
+      enddo
+    enddo
+  endif
+end subroutine DO_TIME_MAX_
\ No newline at end of file
diff --git a/diag_manager/include/fms_diag_reduction_methods_r4.fh b/diag_manager/include/fms_diag_reduction_methods_r4.fh
index 922972cce3..c3bc29296a 100644
--- a/diag_manager/include/fms_diag_reduction_methods_r4.fh
+++ b/diag_manager/include/fms_diag_reduction_methods_r4.fh
@@ -29,6 +29,12 @@
 #undef DO_TIME_NONE_
 #define DO_TIME_NONE_ do_time_none_r4
 
+#undef DO_TIME_MIN_
+#define DO_TIME_MIN_ do_time_min_r4
+
+#undef DO_TIME_MAX_
+#define DO_TIME_MAX_ do_time_max_r4
+
 #include "fms_diag_reduction_methods.inc"
 
 !> @}
diff --git a/diag_manager/include/fms_diag_reduction_methods_r8.fh b/diag_manager/include/fms_diag_reduction_methods_r8.fh
index 25c3031a22..a3e3d68376 100644
--- a/diag_manager/include/fms_diag_reduction_methods_r8.fh
+++ b/diag_manager/include/fms_diag_reduction_methods_r8.fh
@@ -29,6 +29,12 @@
 #undef DO_TIME_NONE_
 #define DO_TIME_NONE_ do_time_none_r8
 
+#undef DO_TIME_MIN_
+#define DO_TIME_MIN_ do_time_min_r8
+
+#undef DO_TIME_MAX_
+#define DO_TIME_MAX_ do_time_max_r8
+
 #include "fms_diag_reduction_methods.inc"
 
 !> @}
diff --git a/test_fms/diag_manager/check_time_max.F90 b/test_fms/diag_manager/check_time_max.F90
index e579bada4f..51e888541c 100644
--- a/test_fms/diag_manager/check_time_max.F90
+++ b/test_fms/diag_manager/check_time_max.F90
@@ -73,7 +73,7 @@ program check_time_max
   do i = 1, 8
     cdata_out = -999_r4_kind
     print *, "Checking answers for var0_max - time_level:", string(i)
-    call read_data(fileobj, "var0_max", cdata_out(1:1,1,1,1), unlim_dim_level=i) !eyeroll
+    call read_data(fileobj, "var0_max", cdata_out(1,1,1,1), unlim_dim_level=i)
     call check_data_0d(cdata_out(1,1,1,1), i)
 
     cdata_out = -999_r4_kind
diff --git a/test_fms/diag_manager/check_time_min.F90 b/test_fms/diag_manager/check_time_min.F90
index cb1406070c..e56e344144 100644
--- a/test_fms/diag_manager/check_time_min.F90
+++ b/test_fms/diag_manager/check_time_min.F90
@@ -73,7 +73,7 @@ program check_time_min
   do i = 1, 8
     cdata_out = -999_r4_kind
     print *, "Checking answers for var0_min - time_level:", string(i)
-    call read_data(fileobj, "var0_min", cdata_out(1:1,1,1,1), unlim_dim_level=i) !eyeroll
+    call read_data(fileobj, "var0_min", cdata_out(1,1,1,1), unlim_dim_level=i)
     call check_data_0d(cdata_out(1,1,1,1), i)
 
     cdata_out = -999_r4_kind
diff --git a/test_fms/diag_manager/test_time_max.sh b/test_fms/diag_manager/test_time_max.sh
index 5a35179b2f..b9a62b4d74 100755
--- a/test_fms/diag_manager/test_time_max.sh
+++ b/test_fms/diag_manager/test_time_max.sh
@@ -29,25 +29,62 @@ if [ -z "${skipflag}" ]; then
 output_dir
 
 #TODO replace with yaml diag_table and set diag_manager_nml::use_modern_diag=.true.
-cat <<_EOF > diag_table
-test_max
-2 1 1 0 0 0
-
-"test_max",      6,  "hours", 1, "hours", "time"
-"test_max_regional",      6,  "hours", 1, "hours", "time"
-
-"ocn_mod", "var0", "var0_max", "test_max", "all", "max", "none", 2
-"ocn_mod", "var1", "var1_max", "test_max", "all", "max", "none", 2
-"ocn_mod", "var2", "var2_max", "test_max", "all", "max", "none", 2
-"ocn_mod", "var3", "var3_max", "test_max", "all", "max", "none", 2
-
-"ocn_mod", "var3", "var3_Z", "test_max", "all", "max", "-1 -1 -1 -1 2. 3.", 2
-
-"ocn_mod", "var3", "var3_max", "test_max_regional", "all", "max", "78. 81. 78. 81. 2. 3.", 2 #chosen by MKL
+cat <<_EOF > diag_table.yaml
+title: test_max
+base_date: 2 1 1 0 0 0
+diag_files:
+- file_name: test_max
+  time_units: hours
+  unlimdim: time
+  freq: 6 hours
+  varlist:
+  - module: ocn_mod
+    var_name: var0
+    output_name: var0_max
+    reduction: max
+    kind: r4
+  - module: ocn_mod
+    var_name: var1
+    output_name: var1_max
+    reduction: max
+    kind: r4
+  - module: ocn_mod
+    var_name: var2
+    output_name: var2_max
+    reduction: max
+    kind: r4
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_max
+    reduction: max
+    kind: r4
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_Z_max
+    reduction: max
+    zbounds: 2. 3.
+    kind: r4
+- file_name: test_max_regional
+  time_units: hours
+  unlimdim: time
+  sub_region:
+  - grid_type: latlon
+    corner1: 78. 78.
+    corner2: 78. 78.
+    corner3: 81. 81.
+    corner4: 81. 81.
+  freq: 6 hours
+  varlist:
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_max
+    reduction: max
+    zbounds: 2. 3.
+    kind: r4
 _EOF
 
 my_test_count=1
-printf "&test_reduction_methods_nml \n test_case = 0 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 0 \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -56,7 +93,7 @@ test_expect_success "Checking answers for the "max" reduction method (test $my_t
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 0 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n &test_reduction_methods_nml \n test_case = 0 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method, logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -65,7 +102,7 @@ test_expect_success "Checking answers for the "max" reduction method, logical ma
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 0 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n &test_reduction_methods_nml \n test_case = 0 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method, real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -73,9 +110,9 @@ test_expect_success "Checking answers for the "max" reduction method, real mask
   mpirun -n 1 ../check_time_max
 '
 
-export OMP_NUM_THREADS=2
+export OMP_NUM_THREADS=1
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with openmp (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -84,7 +121,7 @@ test_expect_success "Checking answers for the "max" reduction method with openmp
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with openmp, logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -93,17 +130,17 @@ test_expect_success "Checking answers for the "max" reduction method with openmp
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with openmp, real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
 test_expect_success "Checking answers for the "max" reduction method with openmp, real mask (test $my_test_count)" '
   mpirun -n 1 ../check_time_max
 '
-export OMP_NUM_THREADS=1
+export OMP_NUM_THREADS=2
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with halo output (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -112,7 +149,7 @@ test_expect_success "Checking answers for the "max" reduction method with halo o
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with halo output with logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -121,7 +158,7 @@ test_expect_success "Checking answers for the "max" reduction method with halo o
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "max" reduction method with halo output with real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
diff --git a/test_fms/diag_manager/test_time_min.sh b/test_fms/diag_manager/test_time_min.sh
index 7049dc6abb..f0305d15a0 100755
--- a/test_fms/diag_manager/test_time_min.sh
+++ b/test_fms/diag_manager/test_time_min.sh
@@ -29,25 +29,62 @@ if [ -z "${skipflag}" ]; then
 output_dir
 
 #TODO replace with yaml diag_table and set diag_manager_nml::use_modern_diag=.true.
-cat <<_EOF > diag_table
-test_min
-2 1 1 0 0 0
-
-"test_min",      6,  "hours", 1, "hours", "time"
-"test_min_regional",      6,  "hours", 1, "hours", "time"
-
-"ocn_mod", "var0", "var0_min", "test_min", "all", "min", "none", 2
-"ocn_mod", "var1", "var1_min", "test_min", "all", "min", "none", 2
-"ocn_mod", "var2", "var2_min", "test_min", "all", "min", "none", 2
-"ocn_mod", "var3", "var3_min", "test_min", "all", "min", "none", 2
-
-"ocn_mod", "var3", "var3_Z", "test_min", "all", "min", "-1 -1 -1 -1 2. 3.", 2
-
-"ocn_mod", "var3", "var3_min", "test_min_regional", "all", "min", "78. 81. 78. 81. 2. 3.", 2 #chosen by MKL
+cat <<_EOF > diag_table.yaml
+title: test_min
+base_date: 2 1 1 0 0 0
+diag_files:
+- file_name: test_min
+  time_units: hours
+  unlimdim: time
+  freq: 6 hours
+  varlist:
+  - module: ocn_mod
+    var_name: var0
+    output_name: var0_min
+    reduction: min
+    kind: r4
+  - module: ocn_mod
+    var_name: var1
+    output_name: var1_min
+    reduction: min
+    kind: r4
+  - module: ocn_mod
+    var_name: var2
+    output_name: var2_min
+    reduction: min
+    kind: r4
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_min
+    reduction: min
+    kind: r4
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_Z_min
+    reduction: min
+    zbounds: 2. 3.
+    kind: r4
+- file_name: test_min_regional
+  time_units: hours
+  unlimdim: time
+  sub_region:
+  - grid_type: latlon
+    corner1: 78. 78.
+    corner2: 78. 78.
+    corner3: 81. 81.
+    corner4: 81. 81.
+  freq: 6 hours
+  varlist:
+  - module: ocn_mod
+    var_name: var3
+    output_name: var3_min
+    reduction: min
+    zbounds: 2. 3.
+    kind: r4
 _EOF
 
 my_test_count=1
-printf "&test_reduction_methods_nml \n test_case = 0 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 0 \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -56,7 +93,7 @@ test_expect_success "Checking answers for the "min" reduction method (test $my_t
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 0 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n &test_reduction_methods_nml \n test_case = 0 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method, logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -65,7 +102,7 @@ test_expect_success "Checking answers for the "min" reduction method, logical ma
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 0 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n &test_reduction_methods_nml \n test_case = 0 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method, real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -75,7 +112,7 @@ test_expect_success "Checking answers for the "min" reduction method, real mask
 
 export OMP_NUM_THREADS=2
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with openmp (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -84,7 +121,7 @@ test_expect_success "Checking answers for the "min" reduction method with openmp
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with openmp, logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -93,7 +130,7 @@ test_expect_success "Checking answers for the "min" reduction method with openmp
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 1 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 1 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with openmp, real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -103,7 +140,7 @@ test_expect_success "Checking answers for the "min" reduction method with openmp
 export OMP_NUM_THREADS=1
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with halo output (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -112,7 +149,7 @@ test_expect_success "Checking answers for the "min" reduction method with halo o
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n mask_case = 1 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n mask_case = 1 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with halo output with logical mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '
@@ -121,7 +158,7 @@ test_expect_success "Checking answers for the "min" reduction method with halo o
 '
 
 my_test_count=`expr $my_test_count + 1`
-printf "&test_reduction_methods_nml \n test_case = 2 \n mask_case = 2 \n \n/" | cat > input.nml
+printf "&diag_manager_nml \n use_modern_diag=.true. \n / \n&test_reduction_methods_nml \n test_case = 2 \n mask_case = 2 \n \n/" | cat > input.nml
 test_expect_success "Running diag_manager with "min" reduction method with halo output with real mask (test $my_test_count)" '
   mpirun -n 6 ../test_reduction_methods
 '