diff --git a/src/io/io_read_particle.f90 b/src/io/io_read_particle.f90
new file mode 100644
index 000000000..c0f0dbdf1
--- /dev/null
+++ b/src/io/io_read_particle.f90
@@ -0,0 +1,43 @@
+submodule (io) s_io_read_particle
+
+contains
+   module subroutine io_read_particle_pl(swiftest_plA, param)
+      !! author: David A. Minton
+      !!
+      !! Writes particle information to a file.
+      !!
+      use swiftest, except_this_one => io_read_particle_pl
+      implicit none
+      ! Arguments
+      class(swiftest_pl),          intent(inout) :: swiftest_plA   !! Swiftest massive body structure
+      type(user_input_parameters), intent(in) :: param   !! Input colleciton of user-defined parameters
+      ! Internals
+      integer(I4B), parameter   :: lun = 22
+      integer(I4B)              :: i, ierr, id, idx
+      integer(I4B), save        :: iu = lun
+
+      associate(out_form => param%out_form, out_type => param%out_type, particle_file => param%particle_file)
+         open(unit = iu, file = particle_file, status = 'OLD', form = 'UNFORMATTED', iostat = ierr)
+         if (ierr /= 0) then
+            write(*, *) "Swiftest error:"
+            write(*, *) "   unable to open binary particle file for reading"
+            call util_exit(FAILURE)
+         end if
+
+         do 
+            read(LUN, iostat=ierr) id
+            if (ierr /=0) exit
+            idx = findloc(swiftest_plA%id(:), id, dim=1)
+            read(LUN) swiftest_plA%info(idx)
+         end do
+         close(unit = iu, iostat = ierr)
+         if (ierr /= 0) then
+            write(*, *) "Swiftest error:"
+            write(*, *) "   unable to close particle output file"
+            call util_exit(FAILURE)
+         end if
+      end associate
+      return
+
+      end subroutine io_read_particle_pl
+end submodule s_io_read_particle
diff --git a/src/io/io_write_particle.f90 b/src/io/io_write_particle.f90
index 23ba897b1..b5f9bbadf 100644
--- a/src/io/io_write_particle.f90
+++ b/src/io/io_write_particle.f90
@@ -1,19 +1,17 @@
 submodule (io) s_io_write_particle
 
 contains
-   module procedure io_write_particle_pl !(swiftest_plA, idx, param)
+   module subroutine io_write_particle_pl(swiftest_plA, idx, param)
       !! author: David A. Minton
       !!
       !! Writes particle information to a file.
       !!
-      use module_interfaces
-      use module_symba
-      use swiftest
+      use swiftest, except_this_one => io_write_particle_pl
       implicit none
       ! Arguments
-      !class(swiftest_pl),          intent(in) :: swiftest_plA   !! Swiftest massive body structure
-      !integer(I4B), dimension(:),  intent(in) :: idx  !! Array of particle indices to append to the particle file
-      !type(user_input_parameters), intent(in) :: param   !! Input colleciton of user-defined parameters
+      class(swiftest_pl),          intent(in) :: swiftest_plA !! Swiftest massive body structure
+      integer(I4B), dimension(:),  intent(in) :: idx       !! Array of particle indices to append to the particle file
+      type(user_input_parameters), intent(in) :: param     !! Input colleciton of user-defined parameters
       ! Internals
       logical, save             :: lfirst = .true.
       integer(I4B), parameter   :: lun = 22
@@ -62,5 +60,5 @@
       end associate
       return
 
-      end procedure io_write_particle_pl
+      end subroutine io_write_particle_pl
 end submodule s_io_write_particle
diff --git a/src/modules/io.f90 b/src/modules/io.f90
index 34ea85824..469d37cda 100644
--- a/src/modules/io.f90
+++ b/src/modules/io.f90
@@ -47,6 +47,13 @@ module subroutine io_write_particle_pl(swiftest_plA, idx, param)
          integer(I4B), dimension(:),  intent(in) :: idx       !! Array of particle indices to append to the particle file
          type(user_input_parameters), intent(in) :: param     !! Input colleciton of user-defined parameters
       end subroutine io_write_particle_pl
+
+      module subroutine io_read_particle_pl(swiftest_plA, param)
+         implicit none
+         class(swiftest_pl),          intent(inout) :: swiftest_plA !! Swiftest massive body structure
+         type(user_input_parameters), intent(in) :: param     !! Input colleciton of user-defined parameters
+      end subroutine io_read_particle_pl
+         
          
          
    end interface