diff --git a/src/cljam/bed.clj b/src/cljam/bed.clj
index e125c03a..3b1b8f26 100644
--- a/src/cljam/bed.clj
+++ b/src/cljam/bed.clj
@@ -1,8 +1,31 @@
 (ns cljam.bed
-  (:require [clojure.string :as cstr]
+  (:require [clojure.java.io :as io]
+            [clojure.string :as cstr]
             [cljam.util :as util]
             [cljam.util.chromosome :as chr-util])
-  (:import [java.io BufferedReader BufferedWriter]))
+  (:import [java.io BufferedReader BufferedWriter Closeable]))
+
+(defrecord BEDReader [^BufferedReader reader ^String f]
+  Closeable
+  (close [this]
+    (.close ^Closeable (.reader this))))
+
+(defrecord BEDWriter [^BufferedWriter writer ^String f]
+  Closeable
+  (close [this]
+    (.close ^Closeable (.writer this))))
+
+(defn ^BEDReader reader
+  "Returns BED file reader of f."
+  [f]
+  (let [abs (.getAbsolutePath (io/file f))]
+    (BEDReader. (io/reader (util/compressor-input-stream abs)) abs)))
+
+(defn ^BEDWriter writer
+  "Returns BED file writer of f."
+  [f]
+  (let [abs (.getAbsolutePath (io/file f))]
+  (BEDWriter. (io/writer (util/compressor-output-stream abs)) abs)))
 
 (def ^:const bed-columns
   [:chr :start :end :name :score :strand :thick-start :thick-end :item-rgb :block-count :block-sizes :block-starts])
@@ -32,25 +55,24 @@
   "Parse BED fields string and returns a map.
   Based on information at https://genome.ucsc.edu/FAQ/FAQformat#format1."
   [^String s]
-  {:post [(and (:chr %) (:start %) (:end %))
-          ;; First 3 fields are required.
-          (< (:start %) (:end %))
+  {:post [;; First 3 fields are required.
+          (:chr %) (:start %) (:end %)
           ;; The chromEnd base is not included in the display of the feature.
-          (every? true? (drop-while false? (map nil? ((apply juxt bed-columns) %))))
+          (< (:start %) (:end %))
           ;; Lower-numbered fields must be populated if higher-numbered fields are used.
-          (if-let [s (:score %)] (<= 0 s 1000) true)
+          (every? true? (drop-while false? (map nil? ((apply juxt bed-columns) %))))
           ;; A score between 0 and 1000.
+          (if-let [s (:score %)] (<= 0 s 1000) true)
+          ;; The number of items in this list should correspond to blockCount.
           (if-let [xs (:block-sizes %)] (= (count xs) (:block-count %)) true)
           ;; The number of items in this list should correspond to blockCount.
           (if-let [xs (:block-starts %)] (= (count xs) (:block-count %)) true)
-          ;; The number of items in this list should correspond to blockCount.
-          (if-let [[f] (:block-starts %)] (= 0 f) true)
           ;; The first blockStart value must be 0.
-          (if-let [xs (:block-starts %)] (= (+ (last xs) (last (:block-sizes %))) (- (:end %) (:start %))) true)
+          (if-let [[f] (:block-starts %)] (= 0 f) true)
           ;; The final blockStart position plus the final blockSize value must equal chromEnd.
-          (if-let [xs (:block-starts %)] (apply <= (mapcat (fn [a b] [a (+ a b)]) xs (:block-sizes %))) true)
+          (if-let [xs (:block-starts %)] (= (+ (last xs) (last (:block-sizes %))) (- (:end %) (:start %))) true)
           ;; Blocks may not overlap.
-          ]}
+          (if-let [xs (:block-starts %)] (apply <= (mapcat (fn [a b] [a (+ a b)]) xs (:block-sizes %))) true)]}
   (reduce
    (fn deserialize-bed-reduce-fn [m [k f]] (update-some m k f))
    (zipmap bed-columns (cstr/split s #"\s+"))
@@ -67,6 +89,24 @@
 (defn- serialize-bed
   "Serialize bed fields into string."
   [m]
+  {:pre [;; First 3 fields are required.
+         (:chr m) (:start m) (:end m)
+         ;; The chromEnd base is not included in the display of the feature.
+         (< (:start m) (:end m))
+         ;; Lower-numbered fields must be populated if higher-numbered fields are used.
+         (every? true? (drop-while false? (map nil? ((apply juxt bed-columns) m))))
+         ;; A score between 0 and 1000.
+         (if-let [s (:score m)] (<= 0 s 1000) true)
+         ;; The number of items in this list should correspond to blockCount.
+         (if-let [xs (:block-sizes m)] (= (count xs) (:block-count m)) true)
+         ;; The number of items in this list should correspond to blockCount.
+         (if-let [xs (:block-starts m)] (= (count xs) (:block-count m)) true)
+         ;; The first blockStart value must be 0.
+         (if-let [[f] (:block-starts m)] (= 0 f) true)
+         ;; The final blockStart position plus the final blockSize value must equal chromEnd.
+         (if-let [xs (:block-starts m)] (= (+ (last xs) (last (:block-sizes m))) (- (:end m) (:start m))) true)
+         ;; Blocks may not overlap.
+         (if-let [xs (:block-starts m)] (apply <= (mapcat (fn [a b] [a (+ a b)]) xs (:block-sizes m))) true)]}
   (->> (-> m
            (update-some :strand #(case % :plus "+" :minus "-" :no-strand "."))
            (update-some :block-sizes long-list->str)
@@ -104,20 +144,20 @@
 
 (defn read-raw-fields
   "Returns a lazy sequence of unnormalized BED fields."
-  [^BufferedReader rdr]
+  [^BEDReader rdr]
   (sequence
    (comp (remove header-or-comment?)
          (map deserialize-bed))
-   (line-seq rdr)))
+   (line-seq (.reader rdr))))
 
 (defn read-fields
   "Returns a lazy sequence of normalized BED fields."
-  [^BufferedReader rdr]
+  [^BEDReader rdr]
   (sequence
    (comp (remove header-or-comment?)
          (map deserialize-bed)
          (map normalize))
-   (line-seq rdr)))
+   (line-seq (.reader rdr))))
 
 (defn sort-fields
   "Sort BED fields based on :chr, :start and :end.
@@ -148,18 +188,20 @@
 
 (defn write-raw-fields
   "Write sequence of BED fields to writer without converting :start and :thick-start values."
-  [^BufferedWriter wtr xs]
-  (->> xs
-       (map serialize-bed)
-       (interpose "\n")
-       ^String (apply str)
-       (.write wtr)))
+  [^BEDWriter wtr xs]
+  (let [w ^BufferedWriter (.writer wtr)]
+    (->> xs
+         (map serialize-bed)
+         (interpose "\n")
+         ^String (apply str)
+         (.write w))))
 
 (defn write-fields
   "Write sequence of BED fields to writer."
-  [^BufferedWriter wtr xs]
-  (->> xs
-       (map (comp serialize-bed denormalize))
-       (interpose "\n")
-       ^String (apply str)
-       (.write wtr)))
+  [^BEDWriter wtr xs]
+  (let [w ^BufferedWriter (.writer wtr)]
+    (->> xs
+         (map (comp serialize-bed denormalize))
+         (interpose "\n")
+         ^String (apply str)
+         (.write w))))
diff --git a/test-resources/bed/test1.bed.gz b/test-resources/bed/test1.bed.gz
new file mode 100644
index 00000000..66cb204c
Binary files /dev/null and b/test-resources/bed/test1.bed.gz differ
diff --git a/test-resources/bed/test2.bed.bz2 b/test-resources/bed/test2.bed.bz2
new file mode 100644
index 00000000..14c0569e
Binary files /dev/null and b/test-resources/bed/test2.bed.bz2 differ
diff --git a/test/cljam/t_bed.clj b/test/cljam/t_bed.clj
index 9dc0c153..facf694a 100644
--- a/test/cljam/t_bed.clj
+++ b/test/cljam/t_bed.clj
@@ -8,33 +8,34 @@
             [cljam.bam :as bam]
             [cljam.util.sam-util :as sam-util])
   (:import [java.io BufferedReader InputStreamReader ByteArrayInputStream
-            ByteArrayOutputStream OutputStreamWriter BufferedWriter]))
+            ByteArrayOutputStream OutputStreamWriter BufferedWriter]
+           [cljam.bed BEDReader BEDWriter]))
 
 (defn- str->bed [^String s]
   (with-open [bais (ByteArrayInputStream. (.getBytes s))
               isr (InputStreamReader. bais)
-              br (BufferedReader. isr)]
+              br (bed/BEDReader. (BufferedReader. isr) nil)]
     (doall (bed/read-fields br))))
 
 (defn- bed->str [xs]
   (with-open [bao (ByteArrayOutputStream.)
               osw (OutputStreamWriter. bao)
-              bw (BufferedWriter. osw)]
+              bw (bed/BEDWriter. (BufferedWriter. osw) nil)]
     (bed/write-fields bw xs)
-    (.flush bw)
+    (.flush ^BufferedWriter (.writer bw))
     (.toString bao)))
 
 (defn- raw-str->bed [^String s]
   (with-open [bais (ByteArrayInputStream. (.getBytes s))
               isr (InputStreamReader. bais)
               br (BufferedReader. isr)]
-    (doall (bed/read-raw-fields br))))
+    (doall (bed/read-raw-fields (bed/BEDReader. br nil)))))
 
 (defn- bed->raw-str [xs]
   (with-open [bao (ByteArrayOutputStream.)
               osw (OutputStreamWriter. bao)
               bw (BufferedWriter. osw)]
-    (bed/write-raw-fields bw xs)
+    (bed/write-raw-fields (bed/BEDWriter. bw nil) xs)
     (.flush bw)
     (.toString bao)))
 
@@ -47,14 +48,42 @@
          [{:chr "chr1" :start 1 :end 100 :name "N" :score 0 :strand :plus :thick-start 1 :thick-end 0
            :item-rgb "255,0,0" :block-count 2 :block-sizes [10 90] :block-starts [0 10]}]))
 
-  (with-open [r (io/reader test-bed-file1)]
+ (with-open [r (bed/reader test-bed-file1)]
    (is (= (bed/read-fields r)
           [{:chr "chr22" :start 1001 :end 5000 :name "cloneA" :score 960 :strand :plus :thick-start 1001
             :thick-end 5000 :item-rgb "0" :block-count 2 :block-sizes [567 488] :block-starts [0 3512]}
            {:chr "chr22" :start 2001 :end 6000 :name "cloneB" :score 900 :strand :minus :thick-start 2001
             :thick-end 6000 :item-rgb "0" :block-count 2 :block-sizes [433 399] :block-starts [0 3601]}])))
 
-  (with-open [r (io/reader test-bed-file2)]
+ (with-open [r (bed/reader test-bed-file1-gz)]
+   (is (= (bed/read-fields r)
+          [{:chr "chr22" :start 1001 :end 5000 :name "cloneA" :score 960 :strand :plus :thick-start 1001
+            :thick-end 5000 :item-rgb "0" :block-count 2 :block-sizes [567 488] :block-starts [0 3512]}
+           {:chr "chr22" :start 2001 :end 6000 :name "cloneB" :score 900 :strand :minus :thick-start 2001
+            :thick-end 6000 :item-rgb "0" :block-count 2 :block-sizes [433 399] :block-starts [0 3601]}])))
+
+ (with-open [r (bed/reader test-bed-file2)]
+   (is (= (bed/read-fields r)
+          [{:chr "chr7" :start 127471197 :end 127472363 :name "Pos1" :score 0 :strand :plus :thick-start 127471197
+            :thick-end 127472363 :item-rgb "255,0,0"}
+           {:chr "chr7" :start 127472364 :end 127473530 :name "Pos2" :score 0 :strand :plus :thick-start 127472364
+            :thick-end 127473530 :item-rgb "255,0,0"}
+           {:chr "chr7" :start 127473531 :end 127474697 :name "Pos3" :score 0 :strand :plus :thick-start 127473531
+            :thick-end 127474697 :item-rgb "255,0,0"}
+           {:chr "chr7" :start 127474698 :end 127475864 :name "Pos4" :score 0 :strand :plus :thick-start 127474698
+            :thick-end 127475864 :item-rgb "255,0,0"}
+           {:chr "chr7" :start 127475865 :end 127477031 :name "Neg1" :score 0 :strand :minus :thick-start 127475865
+            :thick-end 127477031 :item-rgb "0,0,255"}
+           {:chr "chr7" :start 127477032 :end 127478198 :name "Neg2" :score 0 :strand :minus :thick-start 127477032
+            :thick-end 127478198 :item-rgb "0,0,255"}
+           {:chr "chr7" :start 127478199 :end 127479365 :name "Neg3" :score 0 :strand :minus :thick-start 127478199
+            :thick-end 127479365 :item-rgb "0,0,255"}
+           {:chr "chr7" :start 127479366 :end 127480532 :name "Pos5" :score 0 :strand :plus :thick-start 127479366
+            :thick-end 127480532 :item-rgb "255,0,0"}
+           {:chr "chr7" :start 127480533 :end 127481699 :name "Neg4" :score 0 :strand :minus :thick-start 127480533
+            :thick-end 127481699 :item-rgb "0,0,255"}])))
+
+ (with-open [r (bed/reader test-bed-file2-bz2)]
    (is (= (bed/read-fields r)
           [{:chr "chr7" :start 127471197 :end 127472363 :name "Pos1" :score 0 :strand :plus :thick-start 127471197
             :thick-end 127472363 :item-rgb "255,0,0"}
@@ -75,7 +104,7 @@
            {:chr "chr7" :start 127480533 :end 127481699 :name "Neg4" :score 0 :strand :minus :thick-start 127480533
             :thick-end 127481699 :item-rgb "0,0,255"}])))
 
-  (with-open [r (io/reader test-bed-file3)]
+  (with-open [r (bed/reader test-bed-file3)]
     (is (= (bed/read-fields r)
            [{:chr "chr7" :start 127471197 :end 127472363 :name "Pos1" :score 0 :strand :plus}
             {:chr "chr7" :start 127472364 :end 127473530 :name "Pos2" :score 0 :strand :plus}
@@ -174,9 +203,35 @@
   (is (= (bed->str (str->bed "1 0 1")) "chr1 0 1"))
   (is (= (bed->str (str->bed "1 0 10")) "chr1 0 10"))
   (is (= (bed->str (str->bed "1 0 1\n1 1 2")) "chr1 0 1\nchr1 1 2"))
-  (is (= (with-open [r (io/reader test-bed-file1)] (str->bed (bed->str (bed/read-fields r))))
-         (with-open [r (io/reader test-bed-file1)] (doall (bed/read-fields r)))))
-  (is (= (with-open [r (io/reader test-bed-file2)] (str->bed (bed->str (bed/read-fields r))))
-         (with-open [r (io/reader test-bed-file2)] (doall (bed/read-fields r)))))
-  (is (= (with-open [r (io/reader test-bed-file3)] (str->bed (bed->str (bed/read-fields r))))
-         (with-open [r (io/reader test-bed-file3)] (doall (bed/read-fields r))))))
+  (is (= (with-open [r (bed/reader test-bed-file1)] (str->bed (bed->str (bed/read-fields r))))
+         (with-open [r (bed/reader test-bed-file1)] (doall (bed/read-fields r)))))
+  (is (= (with-open [r (bed/reader test-bed-file1-gz)] (str->bed (bed->str (bed/read-fields r))))
+         (with-open [r (bed/reader test-bed-file1-gz)] (doall (bed/read-fields r)))))
+  (is (= (with-open [r (bed/reader test-bed-file2)] (str->bed (bed->str (bed/read-fields r))))
+         (with-open [r (bed/reader test-bed-file2)] (doall (bed/read-fields r)))))
+  (is (= (with-open [r (bed/reader test-bed-file2-bz2)] (str->bed (bed->str (bed/read-fields r))))
+         (with-open [r (bed/reader test-bed-file2-bz2)] (doall (bed/read-fields r)))))
+  (is (= (with-open [r (bed/reader test-bed-file3)] (str->bed (bed->str (bed/read-fields r))))
+         (with-open [r (bed/reader test-bed-file3)] (doall (bed/read-fields r)))))
+
+  (with-before-after {:before (prepare-cache!)
+                      :after (clean-cache!)}
+    (let [temp-file (str temp-dir "/test1.bed")
+          temp-file-gz (str temp-dir "/test1.bed.gz")
+          temp-file-bz2 (str temp-dir "/test1.bed.bz2")
+          xs (with-open [r (bed/reader test-bed-file1)] (doall (bed/read-fields r)))]
+      (with-open [wtr1 (bed/writer temp-file)
+                  wtr2 (bed/writer temp-file-gz)
+                  wtr3 (bed/writer temp-file-bz2)]
+        (bed/write-fields wtr1 xs)
+        (bed/write-fields wtr2 xs)
+        (bed/write-fields wtr3 xs))
+      (with-open [rdr1 (bed/reader temp-file)
+                  rdr2 (bed/reader temp-file-gz)
+                  rdr3 (bed/reader temp-file-bz2)]
+        (is (= xs
+               (bed/read-fields rdr1)))
+        (is (= xs
+               (bed/read-fields rdr2)))
+        (is (= xs
+               (bed/read-fields rdr3)))))))
diff --git a/test/cljam/t_common.clj b/test/cljam/t_common.clj
index a54d73e6..dd17cc3e 100644
--- a/test/cljam/t_common.clj
+++ b/test/cljam/t_common.clj
@@ -146,6 +146,8 @@
 (def test-bed-file1 "test-resources/bed/test1.bed")
 (def test-bed-file2 "test-resources/bed/test2.bed")
 (def test-bed-file3 "test-resources/bed/test3.bed")
+(def test-bed-file1-gz "test-resources/bed/test1.bed.gz")
+(def test-bed-file2-bz2 "test-resources/bed/test2.bed.bz2")
 
 ;; ### TABIX files